Maintence doesn't usually take this long. Guess whoever hosting website is having issues. Sounds like VPS.NET (had 50% uptime with them personally - So I like to put in a good word when I can, and brag how great vps.net are <img src="smileys/smiley2.gif" border="0" align="middle" /> )
Could also be ddos if forum is being hosted on different server, which appears to be.
Wish the guys luck in whatever they doing/sorting out.
EDIT: Okay its hosted with amazon aws, but aws reports no outages.
and paste: nameservers are on the same Class C IP range. This is very bad if you want to be found in the case of outage, or even worst, problems!
Edit2: looks like they having a few issues from what I can find.
Agree lennaert (comment below), would be good if they gave us a HELLO