There’s going to be a Free Weekend for Call of Duty: Black Ops. Starting on Thursday, June 2nd at 10am Pacific Time, you’ll be able to play the multiplayer portion of Black Ops free until Sunday probably. It’s a good chance to try the game out if you’ve been on the fence.
You can start pre-loading the game now. It might not be a bad idea because usually the Steam servers usually get overloaded whenever there’s a free weekend.
If you find yourself not being able to log on to Steam come Thursday or it’s downloading real slow, you can try changing your local region to a random foreign country. You can do that by going to Settings > Downloads + Cloud and then selecting a new region. You could then select something like Japan or Russia.