It's been an interesting experience, now having participated in 2 editions of the contest. I don't think I will enter in future editions, mainly because the way people at Nokia treat the participants. Basically if you're not one of the top price winners, who get monetary awards, you won't get much. As a Judge's Choice Award winner you're supposed to get a membership in their Launchpad program, though I'm still waiting on that. If you're one of the thousands of participants that don't get an award you don't get anything. No recognition at all, not even a thank you.
After the first edition I posted some feedback that was acknowledged, but promptly ignored in the second edition. Actually things went downhill, at least in my perception. I have more suggestions for improvement, but why bother.
I'm not sure what the goal of this contest is for Nokia, but I can tell you that they managed to alienate a few developers. If you look at the number of views on their discussion boards, in the threads related to the contest, you can see that the interest is waning from one edition to another.
There are way better opportunities out there.