The excellent Q2ID plug-in has been updated to support QuarkXPress version 8 files and InDesign CS4. The Macintosh version is available now, and Markzware says that the Windows version will be available soon. I'm happy to see an upgrade available so soon after CS4 began shipping.
This excellent plug-in for InDesign will convert QuarkXPress version 5, 6, 7 or 8 files to InDesign CS3 or CS4 files. Q2ID costs $199 USD. Upgrades from version 2 or 3 are $99 USD according to the Markzware Web site.
Once installed, this plug-in is invisible. To use it, you just choose File > Open from within InDesign, select a QuarkXPress file, and it's converted on the fly and opens as an untitled document in InDesign. More information about this plug-in is available in these previous blog posts.