Opera today gets all its desktop browser versions in sync, with the release of beta 1 of version 7.50 for Windows, Mac, Linux, FreeBSD and Solaris. The software is available for download as an option to the version for the particular platform currently deemed stable, but as it's available to all, Opera must be pretty confident in the beta's stability.
7.50 promises a remodeled UI with smaller buttons and quicker access to browsing features, and comes with chat client, RSS newsfeeds, full text indexing of email, system tray icon/email notifier, spell check support and graphical smileys. There are also improvements to the email client, including enhancements to the spam filter. Full details can be found in the changelog, here.
According to Opera CEO Jon S von Tetchner, "Opera now delivers all mainstream applications iin a single, seamless product ac ross platforms." It's available at opera.com/download, at which point Opera's cunning Norwegian robots will attempt to figure out which particular platform version you're likely to want.