http://www.jim-butcher.com/ is going to get migrated to a new machine Friday evening. This is going to result in a change of its IP address and some downtime that'll depend on how fast the data transfers and the name record change propagates (that's a geek way of saying "where it is on the internet is going to be different, so the site will look like it's down for a day or so").
This site,
http://www.jimbutcheronline.com/, should not be affected during that timeframe -- it's on a different machine already.