It would be supremely embarrassing to Microsoft if Sun gets Solaris for
Opteron out before Windows.
Sun currently has 64-bit Solaris for Opteron scheduled for Dec. of
this year. Word so far is that they are pretty much right on schedule
and that the OS is up and running in their labs.
FWIW I don't think the MS delay is simply an issue of drivers.
They've also delayed Win2003 SP1 for apparently the same reason as
their delay of WinXP 64-bit. All of this actually seems to tie back
in to WinXP (32-bit) SP2, which is continuously being pushed back.
All the future OSes are going to be built off the SP2 code-base and
Microsoft seems to be having no end of problems getting this update
out.
For those that aren't familiar with WinXP SP2, it is a pretty
significant change to WinXP (many have referred to it more as "WinXP
Second Edition" rather than just a service pack). Lots of positive
changes with regards to the basic security concept of the system, but
MS seems to be having HUGE problems making it work. Reports from the
recently released "Release Candidate 2" suggest that this is still
definitely beta software (certainly not an actual candidate to be
released). I suspect that until MS gets these sorted out they aren't
going to try to push the other new OSes and service packs out.