I've been working my way through ME2 with the goal of finishing it before ME3 came out. I've now failed that goal due to life, work, and an EVE Online addiction. Unfortunately, right now I'm like a child on Christmas and I really, really, really want to play with my new toy (ME3). If I just can't seem to hold off on starting ME3, can I still import my character from my unfinished ME2 game into ME3? If so, will my ME2 character level transfer over? Will I get some, if any, bonuses from transferring over my unfinished ME2 character?
No, you can only import ME2 characters once they have completed the game. It should be fairly easy to blast through ME2 though, since most of the content is optional, if you don't mind taking some losses on the suicide mission. Be warned, though, if you don't manage to preserve at least 2 companions Shepard will die, precluding importing.
Your level and perks will carry over into ME3, though the highest level in ME2 is only halfway towards the highest level in ME3 (30 and 60, respectively). You may wish to reset your perks at the Normandy, to be able to customize your character properly from the start. Some ship upgrades also carry over.