Okay, here's an interview with Matt Smith that I found on YouTube:
Click to view
He seems like a really cute guy, and I think his Doctor will be entertaining, but he still seems a bit young. In the first photos I saw, he looked like a creeper, but after hearing him talk, I like him a lot more. But still, Matt, honey, get a haircut! You look like a reject from the auditions for Edward Cullen. Other than that, I think he'll do fine. Actually, a younger actor might put a different spin on the Doctor's genius, making him more easygoing about it. We'll just have to wait and see.