It looks like the "A" record for the www part of the domain has vanished (that happened a couple of days ago...)
If you just use 6speedonline.com the site still works. The fully qualified name is still working for some people because the dns record might still be cached by some servers...
They look to be upgrading the site with new software. I randomly logged in earlier and it looked new. They're probably still trying to get the bugs out.