I am starting by assuming that You are not new to Gmail (beta). I know Gmail has been beta forever, so nothing to miss yet!
Some people have had hard time to migrate to Gmail. I can promise you one thing: Once you jump in, you will love it!!!
So, what is so different about it?
- Threaded Email Inbox
- Label (and move to label) and colorful label
- contacts + chat within
- effective spam filter
- easy integration of google calendar and documents.
- and the whole lot of Labs feature!
If you have been using it, how good you are at it?
Want to see what level do you fit in?
http://www.google.com/mail/help/tips.html

