Presumably you could use this in your own server (where it's most likely to be useful), and since you're not distributing the server binary, you wouldn't be required to hand out source?
I'm mostly interested in it for various sorts of simulations and tools; I rarely write server code. There are a lot of uses for coroutines besides writing webservers :)
(Even in the case of servers, there are a lot of cases where you would want to distribute a server, but not necessarily release the source code under GPL -- games like Minecraft, for instance, come to mind.)
