no.1 XP SP3 is gonna go out soon
no.2 XP SP3 is gonna have (like vista) keys all stored on servers - no generating (generated key wont exist on server or will be found to be used twice - blacklisted)
no.3 XP SP3 is available as testing version, unless you wanna use XP 100% offline then get A CRACKED VERSION RASTER BURN AND DEC0R!