Well, that's interesting... it's not loading here either. I don't check it every day, so I don't know how long it's been down..
I haven't done anything I would expect to cause it to go down. The renewal came due late last year, but it was renewed (and they charged my credit card) so it's not a registration expiration... I did change the administrative contact email info on Friday evening (because I'm changing ISPs) but that shouldn't affect the registration or hosting of the site. (it's not hosted with my everyday ISP)
I'm away from the information I need to login to the control panel right now so I won't know what's up for a few hours.