I assume once we have confirmation that it works with the proper OEM certs and keys. Until then, it's hard to mod a BIOS and be sure that it's going to work.
I have one of the Vaio laptops that is eligible for the free upgrade.. will have to look at the BIOS in Everest and see what I can see... Of course if there is anything specific youd like by all means ask Its currently running Vista Home Pro x64 I think.