Just got it! I can't wait to actually sit down and play it. I'll post what I think about it after I've tried it out. It looks awesome though!
UPDATE: So I've been playing the **** out of this game and so far... it's really good! I loved all the other Advance Wars games so this one is just more and more of that turn-based awesomeness. Hehe, the story mode is cool and quite funny at some parts (cheesy too) and the online is fun too (long games, but that's to be expected). I have yet to try playing against a friend online and test out the chat but i'll be doing that all night tonight. The thing that I like most about the game is it's music. There's a ton of different songs and they all sound great in battle! One thing that bothered me was that they removed the single-card download play features. Now only multi-card play is possible. But that's okay since every strategy fan should own this game anyways!
UPDATE: Just finished a couple games against a friend over wi-fi and it was tough to communicate at first, but once we adjusted how far from the mic we should talk we could hear each other almost perfectly! The game turned out great too, it was a lot of fun for both of us (he won the first round and I won the second

)! Once again, I highly recommend this game to any DS owner.