I've recently turned my attention to Necrons until the new DE codex drops. The Necrons will have a new book of their own before too long, although their current rules have fared quite well in 7th edition thus far.
I should probably wait and see what happens with their codex before I invest a bunch in them (especially if we're only talking a few months) but there are a couple things I know I'm going to need either way. For instance, I still don't have any Necron transports! A couple Night Scythes or Ghost Arks would help my army out tremendously. Both are pretty hardy in their own ways, although a re-balancing of the Night Scythe is inevitably coming with the new book as this is still probably the best dedicated transport in the game. If I make any purchases here it will only be for a single kit until I see the updated rules.
Another Annihilation Barge / CCB kit is a safe purchase as well. They are easy to assemble so you can use both configurations, and both are pretty amazing rules-wise. Again, they could get nerfed but I suspect they'll see slight points increases but remain a solid selection for most lists.
I know I also need another 3 Wraiths to round out that unit. I've already got the bits to make a Destroyer Lord to accompany them. All in all, not a whole lot of investment for a few kits that would open up a lot more options for my Necrons.
Beyond those kits, it gets a little more difficult determining which units to invest in. For example, Flayed Ones. Currently, their rules leave a lot to be desired (especially compared to the rest of the codex) and even worse, they are finecast only. I actually don't think they are completely unplayable as is, but I do think they are situational and you need to run them in a larger pack if you do (so purchasing a bunch of the same, expensive, unposable finecast... no thanks). Of course, there are always scratch building opportunities with regular warriors and a pack of green stuff, but that's still an investment in models and even more so in time to convert the number I need to make them worth it. I don't want to be kicking myself in a couple months wishing I had 3 more squads of warriors rather than worthless Flayed Ones!
I highly doubt that I'll commit to this list or the investment it would require before their new codex comes out (especially with DE right around the corner), but here's a fun list I've been thinking about recently, featuring everyone's favorite flesh-clad robots!
Fleshcrons - 1850pts
Nemesor Zahndrekh +
Royal Court: 4x Harbinger of the Storm, Lord w/ Rez Orb & MS
Vargard Obyron
15x Flayed Ones
15x Flayed Ones
15x Flayed Ones
5x Warriors + Night Scythe
5x Warriors + Night Scythe
6x Wraiths (2x Whip Coils)
Annihilation Barge
Annihilation Barge
The list is built around Zahndrekh and tries to maximize his special rules, specifically Adaptive/Counter Tactics and Phased Reinforcements. For those unfamiliar with these special rules, Phased Reinforcements allows any number of my units in reserve with the Deep Strike rule to enter play via Deep Strike immediately following any enemy unit that arrives from reserve that turn. Adaptive/Counter Tactics basically allows Zahndrekh to strip a number of special rules from an enemy unit within line of sight (i.e. Counter-attack, Hit and Run, Stealth, etc.) and allows him to grant one of those special rules to one friendly unit. Some pretty cool rules that open up a bunch of options, and we haven't even gotten to his perks with Obyron.
The Flayed Ones and Wraiths can be held in reserve since both have Deep Strike. Turn 2, your opponent rolls a unit on from reserve and you now have the option to drop 45 Flayed Ones and 6 Wraiths anywhere they can fit -- you can drop a unit in as a road block (a literal meat shield) or distraction, go after weaker backfield units, or claim / contest any objective. What's great about this strategy is you have the benefit of seeing your opponent deploy and take their first turn, so you'll have a sense of what they are trying to accomplish with their army; with that insight, you'll be able to place anywhere from 6 models to 51 models exactly where you need to disrupt and foil your opponent's plan. As long as your opponent has reserves, you have the option to bring on any and all of your deep strike reserves during your opponent's turn!
Why would you ever want to do that?! Well it may not always make sense to use this rule, and thankfully you don't have to if you don't want to. But for assault-based units, like Flayed Ones and Wraiths, it can be very good to show up during your opponent's turn since they can't assault the turn they arrive from reserve anyway, might as well satisfy that requirement during your opponent's turn so they are free to launch an assault during your next turn! This is also why you should take large squads, so they can endure a round of shooting before diving in. On your next turn, you can buff them with Furious Charge or Hit and Run with Adaptive Tactics, then all of the sudden you have a much scarier threat for your opponent to deal with.
With all the chaos of dropping flesh-crazed robots during your opponent's turn, they wont even notice your weatherman-star (Lord & 4 Stormteks joined by Obyron for Deep Strike shenanigans). 4 voltaic staves that can drop anywhere each turn, even if they were locked in assault! Obyron's Ghostwalk Mantle is the key here and the interaction with Zahndrekh is pretty fun (no scatter if Deep Striking within 6" of Z, and Obyron coming to Z's rescue when Z gets charged). This unit should prioritize heavy armor, anything that Tesla Destructors can't hurt.
Now the meat and potatoes of the list. What can you do with a horde of Flayed Ones? They are kind of a wild card unit that will depend a whole lot on what your opponent is playing. They have a very respectable amount of attacks, so against weaker, non-dedicated assault units they should fare well just on weight of dice alone. With a Furious Charge buff from Z, these guys become strength 5 on the charge and can really start to threaten tougher units and vehicles with average armor. They also have relatively good staying power at T4, 4+, and Reanimation Protocols. If you free up points to join a Res Orb to the unit they become even more difficult to remove, and when taken in large squads (~20) they provide a solid footprint for some board control. But the best thing they have going for them is the deployment options with Infiltrate and Deep Strike. On their own, I don't think they are worth it at 13pts a piece; not when you can get a warrior with Gauss (which can threaten almost anything) for the same price. It's really Zahndrekh and his special abilities which can make Flayed Ones playable. Imotekh also has a special rule specifically for Flayed Ones, but it's incredibly random and not nearly good enough to base your strategy around.
Without a doubt, Flayed Ones need an update more than any other entry in the current Necron codex. They just don't quite seem complete or well thought out in their current incarnation. I think this list is wonky, fun, and if played smart has the tools to deal with a variety of armies & lists. But it's unfortunate when you have to take a named special character just to make another unit playable. I do hope Flayed Ones are fixed in the next codex as the unit can add a lot of character to a Necron army.