If you buy a new one, it'll be the last year model. Depreciation will be terrible when the new model comes out and you'll be driving yesterday's model in a few months.
It's all up to you. I bought mine new a year after graduating too. But I had to buy new as it was a brand new model. I'd personally recommend getting the new one that comes out next year if you're doing new. You'll get to drive the "latest" body style for 7 years.
The photos for the new ones look amazing. Considering that the new coupe will be using essentially the same engine as in the outgoing 335i, I'd feel good about getting the new model. Unlike the current 335i back in 07, it was the first time BMW had a turbo'd inline 6. Great engine but there were it's kinks early on, mostly which have been resolved.
If you're set with the e92, I'd recommend going with an 07 to 10 e92 335i for the N54 motor (or new 335is). They're awesome motors with great potential when modded.