Xserve G5 with 10.4 to Xserve Intel with 10.5

Okay, I just joined the list and I did a search for the question but did not see an answer. The univesity I work for is looking into replacing a Xserve G5 with 10.4 to a Xserve Intel with 10.5. We are thinking that aside from speed there will also be an issue with 32 to 64 bit programs. My question is, and please link previous inquiries if they exist, is will the G5 run Leopard? Any suggestions? Troy in Portales, New Mexico agnustic [ at ] gmail.com