I don't think Red Hat are the only developers switching to X.org. For one thing Debian is also. Furthermore key people like Jim Gettys and Keith Packard are associated with X.org. These guys have been working on X related stuff well before XFree86 even existed.
Red Hat is not a "developer," it's a distributor: someone who repackages and markets somebody elses product.
And so far, that's all X.org has done, too, with XFree86's code.
As I've already said on this thread, those vendors/distributors are switching to X.org because it is an organization that is vendor-oriented and sponsored by the hardware and software manufacturers, whereas XFree86 is an independent community of volunteers. <http://www.theinquirer.net/?article=14511>
You might want to check out this thread on XFree86 in regards to the other developers at X.org. He basically sees it as the corporations lining the developer's pockets to push X.org this way or that. I'm glad that I could find some balance on this issue.
<http://marc.theaimsgroup.com/?l=xfree86-forum&m=108542018030529&w=2>
The thread started with this message, which I thought made a pretty interesting point about fixing the license (basically saying to take it back to the modified BSD license, because any XFree86 additions to it are essentially redundant):
<http://marc.theaimsgroup.com/?l=xfree86-forum&m=108183150511654&w=2>
Peace, William