Why is Gmail Still Called Beta Software?

I have been using Gmail since early 2005. I believe I was an early adopter. It was called "beta" software back then. Perfectly sensible. OK, it is late 2007. I have over 5000 messages in my inbox (and that is even after a few month hiatus where I went back to Hotmail). Gmail has millions and millions of users.

So, why, oh why, is Gmail still called "Beta"?

I would really appreciate someone giving me an answer to that question. My thinking is that it is an "out" for Google in case something goes wrong with Gmail --- "Oh, it is beta software. Use at your own risk. If you are adverse to beta software risk, wait until the official release of Gmail, which will be......" NEVER!! :-)