Microsoft has officially released a beta build of the popular MSN Messenger 6 program (spotted @ Neowin). For over a month the beta has been available both externally (non-officially) and internally (officially) and has knocked up 2 million downloads according to a leaked Microsoft memo.
If you haven't had the chance to try the new client then here's your chance, the build number is 268 making it slightly updated than the leaked builds (250, 256 and 263).