The fine folks over at Macenstein spotted this special deal: a free license for the Mac version of DivX Pro, if you send in your email address today -- a $20 value. I can't see the end-of-offer indication on the site, but I'll take their word for it.
With the Pro version you get the free player (naturally), plus DivX Converter for batch encoding and the DivX Pro codec for export from QuickTime Pro-aware applications. Based on the theory that you can never be too rich, too thin or have too many video compression applications, it's worth checking out.
Thanks Jonathan & Nik!