Yes, absolutely.
I have two Windows 8 clients on a 2003 level domain myself with 2003 and 2008R2 DC's. The only issue I had originally (when it first came out) was updating my WSUS server so that it could receive and push updates to my Windows 8 clients. There was a patch or special install.
If that's all I've seen on 2003, 2008R2 should be easy. No weirdness or inconsistencies.