A reply from Edward at Xara as to why some are seeing the new site and others aren't:

Phil - unfortunately we have been having problems with a secondary DNS server which seems to be pointing to the old Xara site, even though it's been told to point to the new one. Apologies for the problems, but it should be working smoothly by tomorrow - it has to be that long because making changes to a DNS server takes time to impact on all the ISP servers all over the world.