We are a non-profit org and because of limitations on purchasing server 2008 i have ended up with a Standard and an Enterprise copy. My question is: I have one domain controller that has a Standard 32-bit OS. Can I have an Enterprise 32-bit dc added to my only domain (it won't be a RODC)? Will they be compatible? I'm also planning DFS Replication on these dc's. Thank you for your help.

AFAIK, only one can be the DC, the second would have to be the SDC