The beauty of Google is that they never release anything. Almost all their software is in beta, which absolves them of almost all sins: if the software doesn’t work or if they want to come out with new features every day or if they want to yank it entirely, they can. It was never released! You are using it at your own risk! The problem is that when they unveiled a web-based e-mail product, they changed the the equation a bit. They want you to store everything. They give you the space to do it, they even let you download it if you want, and now you can import mail from other services too!
This is great and would be awesome if it were bulletproof, but unfortunately, someone exploited a bug in firefox (don’t even get me started on the open-source version of this discussion), that deleted people’s mail. This would be bad with any mail system, except all fee-based systems (released systems) include backups for just this occurrence. Google doesn’t, but then again, they don’t have to, they are BETA! Mail is just a platform to deliver ads to you, they can’t make money on it as a pay service, so there is no incentive for them to ever release it.
What amazes me is how many people not only use GMail as their primary (if not only) mail service, but actually use it for their business mail as well. That is crazy-insane, especially in light of the privacy issues as well (a beta service would guarantee no damages to you if someone breaks into your mail or if Google decides to peruse it themselves).