For now, I don't think I'll be doing anything with it anytime soon. First of all, I'm currently starting to finish a site that actually earns me money so that has priority of course. Other than that, I am indeed fairly serious about it in the sense that I would like to earn my money with web designing/developing until I found something better, but it's not like it's a very important part of my life, and I've got enough other things to do, some of which have the potential to eventually earn me some money as well. It also doesn't really fall under the 'good cause' category that would make me consider it more severely. The portfolio is nice too of course but if I do some of those other things, I've got a more diverse CV and, well, a more diverse life and experience I suppose.
And at least I'll have a portfolio soon which does what I want it to do; show what I'm capable of doing right now, so it's not like I'm desperately in need of one anymore.
I don't want to discourage people from offering their free projects though. Right now I've got enough to do but things will change, so feel free to keep the requests coming, if only so I can keep them in mind and get back to you when I'm bored. To be honest though, if anyone wants me to have anything serious done anytime soon, I will probably involve a payment or some other advantage of some kind for me. A possible exception is if it's a good cause that I think will also be effective.
I'm pretty cheap though, compared to the professionals :-)