The Unix Guardian says: HP announces support for Solaris 10 on Xeon. The reasoning being that Sun has no Xeon h/w of its own at this time. Interesting, as in my job the x86/x64 server h/w is all HP, running either Windows or Linux. Our ERP systems all run on SPARC/Solaris, though.
And the same article mentions Transitive chalked up HP for its h/w emulation technology, adding them to the matrix of multi-platform cross-overs.