For me:

3DS - Nothing, already sold. Got 2 on preorder.

NGP - low price, compatibility with my PSN titles that I already bought, PS2 classics on PSN - ideally the HD version with trophies but will settle for OG versions, cross game compatibility and progress saving on the cloud on Madden, FIFA, NBA2K and MLB The Show, and since UE3 is there, major UE3 games like  Bioshock and ME spin offs. Ideally I would want Gears, but I doubt MS would allow that.

Games....

3DS -> already preordered

NGP ->  monster hunter, persona, FF8/9 remakes, and lots of rpgs in general... & $250  price.

3DS - price drop in an year or so, and localization of layton, none of the other games or features interest me

NGP - Already sold on the HW, so much potential, graphics and gameplay wise. It has UC, KZ to start off with with Gravity Daze looking really interesting. I will buy one (given how my wallet is doing at the time) within the first 3-4 months of release

im ready to pre order at least one ngp, im planning to take my first one apart to check the hardware out. for me to buy a second (for games) they'll have to deliver on some of the games that theyve already said were going to be on it

i dont see myself getting a 3ds for quite a while, theyre gonna need some games. the only game i want right now is zelda (maybe resident evil also, but im not too sure yet), its gonna take a lot more than one (or two) games to get me to buy the hardware to run it, especially when i already have the game on a different platform

either way, ill probably grab the one with lots of rpgs, i was very pleased with the psp rpgs, and look forward to more of them on the ngp.

3DS - preordered

NGP - I am sold, but I need serious cash. And since I'll be paying for college during its lifetime... >_>

You want NGP to be cheap but do things even $400 devices can't do. 

Zelda OOT among other games Sold me on 3DS

NGP --> Already Sold, Beautiful & powerful hardware, A nice lineup of games and we haven't seen e3 yet.

Sorry to let you down.

drop in price...a 3ds would cost me the same price that i paid for my wii

i'm buying both if the games are good.

if the launch line-up for NGP isn't good, then i'll wait for a few months before buying it.