Only a few accounts have received it so far, but it’s a minor change on the outside (albeit it has been re-engineered under the hood) The only noticeable changes are its improved speed (it’s really fast now, as it caches everything). Interesting to note is that it IS caching that’s doing this, and not some other trick. The first time you click a label, it lags a little, but subsequent (in the same session) loads are near instant. The other big improvement is the Contacts section pictured below (and don’t even think about spamming me!)
So far it seems a little rough, and crashed on me once, but it’s good to see that google isn’t pulling a microsoft and pulling the plug development when they get in the lead, vowing only to improve when they have competition (ala IE vs Netscape)
You’ll be able to tell if you have it if you see a ‘old version’ in the top corner like in my pic.