I have to say the Batlle.net Desktop Launcher App Thingie is kinda cool. You can login once then launch all your Blizzard games from one place without having to re-login. Even across restarts.
And you can install your games without downloading that awful launcher for each one of them.
And it has subtle effects that change with every game you select AAAND you can see your online friends without launching the game.
Aaaaand you can see all the news relevant to each game.
Bravo Bilzzard for making a cool app. I wonder if you are thinking of taking over the world like Valve!