"Microsoft have released a new build of Windows XP SP2 to official beta testers this evening. Although it was announced that the next build would be RTM it seems Microsoft want to gain some last minute feedback before the RTM in August. This build is interim between RC2 and RTM and will not be made available to public preview."

I'm using it as we speak. Some of the security stuff gets annoying (but it's probably a Hail Mary for the average user) after a while but overall it's very cool, I haven't found any problems with it outside of that small complaint.

Thats nice, but does it really add something ? I mean, is it worth installing ?

short answer YES! SP2 will include Driver updates security patches and support for newer devices out on the market. You don't have to update but it's reccomended. Also for you McAfee users there will be a newer version of VisrusScan (V8.0) released which will work with SP2 , but you need ti have a 64 bit chip for it to work