Surely there are downloads on EN World that make use of non-SRD 3e material, and I assume 4e material as well.
I wouldn't know yes or no, but my gut feeling is that if the mods found this to be the case, they'd take it down...which is probably what WoC would ask for.
In any event, I think your "there's nothing worth pursuing" is evidence of a lot of assumptions that I, for one, am not willing to make. If WotC decided EN World was cutting into their profits, could Morris afford to defend against WotC? If not, does WotC actually have to win a legal battle to close EN World's virtual doors?
Not so much assumptions as personal observations. I'm not sure of what besides some possible downloads that ENWorld has yet to remove that WotC could point at and say "this cost us money" and initiate a lawsuit.
Whether or not Morrus has the funds to win/survive a WotC suit is something only he could answer.
There is evidence, as linked upthread, that CK had a good relationship with WotC, too. After all, you generally don't recommend people go to a website that you think is causing you problems, do you?
And we have zero idea as to what went on before this time- nothing? A bunch of C&D letters? Prior threats of legal action? We simply don't know.
Nor, again, does your post answer my questions:
(1) Could WotC make the same sort of claim against EN World?
(2) How would you feel about that?
I DID answer that- I've seen nothing here WotC could hang a lawsuit on.
To file a lawsuit, they would have to allege facts supporting their claims if being damaged. With, as I pointed out, nearly all of the speech I've seen here falling into constitutionally protected safe harbors, there's nothing to allege from the forums. Given their history of mod enforcement, ENWorld would win on the merits (or possibly even an outright dismissal) that they did give their best efforts to keep the site infringement free.
So I'm asking you, is there some form of infringement you've seen here go unpunished that you feel could endanger ENWorld? Because I haven't seen any.
As to how would I feel?
Well, given my personal assessment of ENWorld's environment, I'd think WotC would be foolish to go after the site for a variety of reasons, most boiling down to I haven't seen anything they could sue for. They could file the case, no doubt, but I suspect it would be dismissed for lack of alleging facts to support their allegations, case over.
I guess I'm saying that, based in my perceptions of ENWorld, you're asking about a scenario that has less than a 10% chance of occurring.