Clark's take is interesting as he pretty much says the 3e market isn't good, he won't support Pathfinder until it's actually completed and out, and that he won't use the current GSL. He's also very sincere in supporting WoTC, while also wanting to make sure the GSL doesn't make his own rights an issue.
My guess is that he will not try to use the "games can't be copyrighted" argument some publishers are using. I know he's criticized OSRIC in the past, feeling it's not something he'd touch due to legal issues, so I doubt he'd ever try to adapt to 4e using the OGL. As a lawyer he understands the issues involved.
The good thing for him is that this ISN'T his full-time job so he can afford to wait and see. (The only negative is market share loss as some people "move on", but hopefully people won't have short memories).