I just got my grubby paws on the Necron Codex over the weekend and I have to say, I like what I'm seeing and here's why...
Fluff-wise, I kind of like it. I know a lot of people out there are totally turned off by the Tomb Kings in space vibe, but I kind of like having Necron Lords all over the place each with their own characters and foibles. It's a complete about-turn from the fluff from the previous codex, but I think this one gives it a bit more scope for depth and expanding the fluff. That having been said, I've always been pretty easy to satisfy, fluff-wise. The army list, however...
Necron Warriors are now 13 points. 13 points! That pretty much decided how I wanted to play this. I'd always imagine Necrons as rank upon rank of Necrons Warriors, plodding inexorably forward, blazing away with their Gauss Flayers, weathering horrific amounts of firepower, and that's just what they do. Here's an example of some fun I had with Warriors:
1) Took a squad of 20 Warriors, accompanied with a Necron Overlord with the Phaeron upgrade and a Resurrection Orb. What this means is that those 20 Warriors now come back on a 4+ and are Relentless. Behind said squad is a Ghost Ark, happily feeding new Warriors to replace the ones that refused to get up.
2) Enemy shooting phase, the squad takes some ranged abuse. No biggy, about half get back up, but here's the thing. I take the casualties from the rear ranks and put the reanimated ones in coherency in the front. I've now effectively moved forward ~3" (2" for coherency, ~1" for the base) and it's not even my turn yet.
3) My turn and the Ghost Ark activates. At the start of my Movement Phase, I place 1D3 Warriors in coherency, again in the front. Since my opponent opened fire during his turn, I've now crept forward 6", and I still haven't carried out my Movement Phase!
This kind of shenanigan is a pretty useful way to make otherwise unwieldly blobs of Necron Warriors surprisingly mobile. And with 20 relentless Warriors, you can glance pretty much any vehicle to death or near-uselessness in a salvo.
Of course, it's not all hunky dory. For all their resilience to ranged abuse, swarms of Warriors are pretty vulnerable to a reasonably strong assault. A few power weapons to bully the Warriors, and whoops, there goes the combat! And with an Initiative of 2, they're very, very prone indeed to getting taken apart in a Sweeping Advance.
I'm still experimenting with the army list, but for now, I'm leaning towards an army centred around 2 Phaeron-led swarms of Warriors marching around the battlefield shredding everything their path with an absurd number of Gauss shots. The list has plenty of scope to field all sorts of fun gadgets (the Doom Scythe looks SO fun!) but for now, I've pretty much set my sights on a very Warrior-heavy Necron army for early 2012.