I was lucky enough to obtain a GMail account to beta test, and damn, I love it!
Ever since I started using Google, Ive always loved how clean and simple it was. The idea of Google Text ADs is awesome too. I never mind browsing a site that has Google text ADs. They dont slow down the speed of the page when its loading, and they dont distract your attention away from the content of the page.
Oh, back to GMail; its awesome! As soon as GMail goes public, I highly recommend you get an account! Thats my mini-review of GMail. =)