Google are starting to roll out their new and improved new look GMail 2.0 to a few selected users. you may be one of those selected users. To find out, login to GMail and look for a "new version" link at the top of the page.
The other new feature that i am especially liking is the filter. The old "more actions" drop down box now contains a "filter messages like these" option which will open a filter options box.
Does anyone else find it sad that GMail 1.x didn't make it out of beta? :'( *tear*