Manish, thank you. I have looked at that link several times and never noticed the supported OS section. I also found the very helpful PDF last night.

http://www.cisco.com/en/US/docs/unified_computing/ucs/interoperability/matrix/hw_sw_interop_matrix_seriesB_111.pdf

While the official answer may be that it is not supported, I have to say that it is a BAD answer.  Our local Cisco SE said it was due to Microsoft discontinuing new certifications for 2003.  So what?  W2K3 is a huge part of my environment.  While not having the drivers won't stop our implementation of UCS, it is causing us to think about not moving some systems to UCS.  We do a lot of W2K3 clustering so having Palo drivers would be very beneficial.  Now, we may have to lose some redundancy so we can keep our heartbeat and servers traffic separate.

A good answer to the original question would be, "There are currently no Palo drivers for W2K3, but we are working on them."

Adam