Since buying the 3DS at launch I cant make up my mind if it's worth the purchase (yet) or not. On day 1 I would have said yes because it really is a nice system and the 3D does work! On top of that the AR cards were a nice surprise. They're a great example of what the 3DS can do. But after about a week that would've changed to no as there was just very little to play. I even got fed up of taking the 3DS out just to see if anyone else would get picked up (they never did).
Probably like a lot of people I bought one hoping Zelda OoT would land close to lauch... but it didnt. It's safe to say I barely touched the system from the day it arrived until the day OoT was launched. But around E3 time when the store opened things got more interesting. I purchased Zelda DX and played that for hours on end, then not long after OoT was finally released. Around that time I would've said "yes buy one". The 3D works very well, it's a great game and the extra features make it woth another play through if you've played it before. The only flaw is probably one of my own making. The 3D keeps giving me double vision even a low setting! I'm pretty sure my eyes need testing... so really that's a positive right?
But saying that is it worth buying an expensive system for 1 game? Really in my opinion unless you're a Zelda fan you're probably better off waiting until around Christmas time. At least then there's Zelda, Mario Kart, Kid Icarus (USA) and Super Mario with other titles much closer to launch (Resident Evil etc). The 3D is nice but I dont think it's a big enough reason alone to pick up the system, like any console software is key.