Not to panic anyone but, speaking as a gen-u-wine computer professional, "stuff" happens. Of course, I'm sure that RealSkiers.com's host is performing regular backups, but...
If you have been enjoying the PMTS forum threads as much as I have, you might want to save copies of your favorites to your hard drive.
Personally, I'm also saving Harald's posts separately. He's writing a new book right before our eyes.