With Gmail, if something is wrong in the code, they can fix it and everything is fine in a matter of hours/days. With Chrome, if there's a problem in the code, they can fix the bug, but then it could be months or years before people actually upgrade Chrome.

Desktop software requires a higher standard because you can't just fix things that are wrong.

Chrome actually updates itself automatically in the background.

Tell me about it. GoogleUpdate.exe keeps coming back no matter what I do.

That was essentially the reason I found this interesting. Considering (as another comment correctly states) Gmail has been in Beta for 4 years. Google almost singlehandedly started the "perpetual beta" mantra, and suddenly, Chrome, which happens to be a complex piece of software, is out of beta.

Makes me think... Why?

Chrome has been in development since spring of 2006. It has been around much longer than it has been public.

Just a guess, but they may feel that having the beta label on a downloadable app tends to turn people off, whereas people don't mind beta web apps (its the norm and they won't screw up your system).

It could be something simple. It could be that the people who decide whether Gmail is a beta or not aren't the people who decide whether Chrome is a beta or not.

Because It is a desktop software, not a web application.