Tsvangirai is a good pick, but it wouldn't have done all the good you would think.
Nothing will get rid of Mugabe until Mugabe is brain dead. Scratch that. I think he IS brain dead, and yet there he remains.
Tsvangirai hasn't DONE anything either, not in the sense you're saying. He is the PM of Zimbabwe. He is under a lot of scrutiny and pressure, sure, but so is Obama. The Peace Prize is not the same as the others because it is awarded on a different basis. It's not given for a specific accomplishment, it's given to someone who is doing the most for lasting peace. In the opinion of the committee or whoever, it's Obama, probably because he wants to get rid of nukes.
There is nothing wrong with that. You can bitch all day about how Obama doesn't deserve it but the fact is any person on Earth can be criticized just as much. The award isn't given by popular demand it's given to whoever the prize committe thinks deserves it. If they thought that was Obama, then by all means we shoud be happy for whoever got it.
I think one of the most important reasons why he DOES deserve it is because he is dispensing with hateful rhetoric that has set the tone for the world stage for the past decade. He is reaching out and trying to creat a global community, in a word, peace. Just because assholes like Ahmadinejad and Mugabe aren't returning the gesture doesn't mean he shouldn't be lauded for going there.
Does this make Obama as saintly as Desmond Tutu or some other prize winner like that? No. The man is a sitting president. He is sure to do something that almost no one will applaud, just like TR or Woodrow Wilson did. But TR and Woodrow Wilson are my two favorite presidents incidentally, and after 4/8 years, we'll see if I feel the same way about Obama.