As others have said - the Blackberry has better email support (your work email system may not even support Droid depending on how strict they are with security settings), a better keyboard, is smaller/lighter, and generally has better battery life.
The Droid has a bigger/higher resolution capacitive touch screen, more apps available to download, a superior browser, faster processor.
Very much depends on what you look for in a phone. For what its worth, I bought a Tour last September, tried it for two weeks, and ended up returning it in favor of waiting for the Droid. Which I sold five months later.