This may have absolutely nothing at all to do with it... Then again, Microsoft just released a whole boatload of security patches this month. So maybe one of those patches had something to do with why everyone suddenly experienced the site slowing down.
I just added http://www.paflyfish.com to my list of trusted sites and it's running much faster.
The site uses a lot of scripting, so I am guessing that if the site isn't trusted IE runs these scripts differently than if the site is trusted.
I haven't noticed the same problems on any other site, but, I don't think that any other site I visit works quite the same way as this one.