Scott Ehrlich wrote:

At work I am building and will be responsible for maintaining 64-bit Centos 5 systems. For desktop use, I'm debating between 32 and 64-bit versions.

I know such applications, such as flash for firefox, are first honed for 32-bit systems, then evolve for 64-bit. What other obstacles could I expect to face _if_ I chose 64-bit over 32-bit for the desktop?

That really is the only major problem ... that several packages do not exist in x86_64 and you will have to maintain both i386 and x86_64 RPMS installed to get the items that do not exist for x86_64.

I'd be installing on an 8 GB dual core high-end Dell desktop.