I'd highly recommend RE: Mercenaries as well. I read a few reviews that complained about the very "drawbacks" you mentioned and decided not to get it originally. I caught it on sale for 20 bucks and went ahead and picked it up.  125 hours of gameplay logged in Mercenaries now and I'm still enjoying it. I didnt play Mercenaries this much on RE4, but for some reason I've become addicted to this game. Very fun and smooth controls, very nice graphics, multi-player, and alot of acheivements/medals to fool around with if you're interested.

I am sure Advance Wars will come out within a year or two.  I believe the GBA and DS both had 2 Advance Wars.  I've played all the Advance Wars except the first one.  I'll probably have to pick it up just so I can say I've played and beaten them all.

Alright there are two titles you need to own this holiday season. If you have a 3DS and don't own them shame on you, that or you must just hate Mario.

1.MarioKart 7

2.Super Mario 3D Land

other titles you should look at or must own

3.LoZ:OoT

4.Rayman 3D (If you never owned the second Rayman before)

5.Street Fighter or Dead Or Alive:Dimensions (If you like fighting games)

Other decent titles include Monkey Ball 3D, StarFox64 (A must for any StarFox fan) Nintendogs+Cats if you like virtual pets.

Everything else is alright or plain suckey but their are plenty of gems out there.

I have Street Fighter 4 and Ocarina of Time. SM3D Land and MK7 are both the ones to have though, so I'd buy those first!

I have Street Fighter 4 and Devil Survivor Overclocked and both are great

Star fox 64 3d is excellent,also really enjoyed ridge racer its got an old school arcade feel to it,the 3d is great and its good for short bursts of gameplay.If you like footy fifa 12 is a really solid effort too,a nice alternative to the console versions.

Only game I can think of that might be worth recommending (that hasn't already been mentioned) is Mario and Sonic at the London 2012 Olympics. It isn't out until next year but could be a decent purchase.

I have only played three 3DS games and they are all recommendable:

The Legend of Zelda Ocarina of Time 3D
Super Mario 3D Land
Super Street Fighter IV 3D Edition

Also, I think you should try some "lost" gems of the DS on the 3DS like Okamiden or Solatorobo, which run better when played on the 3DS, mainly because of the higher specs, adding that the controls are better due 3DS's Circle Pad.

And the most important of all, enjoy it!

If you like soccer (football), PES 2012 is the better option right now.

Resident Evil Revelations, Super Mario 3D Land, Mario Kart 7, and Zelda Ocarina of Time are mandatory for every 3DS owner ! These ones are excellent.

Other games that I´d recommend:
Metal Gear Solid Snake Eater
Dead or Alive Dimensions
Street Fighter IV
Devil Survivor Overlocked

I reccommend you do not go on a gaming shopping spree and just wait until Uprising. There should be plenty on the 3DS itself to check out and download before it releases. Check out some of the e-shop games first :D