Former WM user, switching to Droid today. My phone will be delivered today and I can't wait to start playing with it.
Welcome, mbutler! You'll find this to be a very friendly place full of great people and information! The possibilities are endless for customization. So read, read, and read some more. You'll be amazed at how much you can teach yourself by reading the threads here in the forum! Here's a good one about app recommendations.
Forget the top 5, list ALL of your apps
Hope you enjoy your time here and try to remember to eat and sleep tonight!