The non-beta Flash Player 9 version is now available for download. The press release says that Novell and Red Hat will package this version with the distributions. However, it is still not feature complete (via Ryan Stewart) and seems to be released because of demand for a non-beta version. Tinic also lists things being worked on.
I had installed the beta version and I cannot call it a smooth ride. I cannot say much about this one without using it for about a month or so. One of the sites that I can now use smoothly is Google Analytics, which has troubled others too. Otherwise I do not use a lot of flash sites, but it is comforting to know that it is being attended to.