if you are looking for the official x2 bios, yes that is the most current...however there is a beta version of the newest x2 bios...you can try the new beta if you wish, but don't be surprised if there are some bugs in it...the beta is x2_5022 if you wish to try it out.
I agree with mdsup, stick with the offical build, one thing you shouldnt go beta with is bioses because you don't know what can go wrong with those. With beta bioses, if something goes wrong it may not be a simple fix.
