Rockwell Software has updated tech notes regarding the compatibility of software packages with Windows 7 and the Windows XP Mode included with Windows 7. I covered some of the potential issues using XP Mode and Windows 7 with older versions of the software in this post series: Windows 7 or XP or 98 or whatever with Automation Software (part 1 of 3). Some of that information is dated based on these new tech notes.
The gist of the updates is some older versions of RSLogix programming software (5, 500, and 5000) work on Vista and Windows 7 (32 bit). Also a number of software products have been tested and are now supported in XP Mode on Windows 7.
Look for Answer ID 67020 and 341918 on the Rockwell Automation Knowledgebase for more details.
I personally still feel that VMWare is the best way to reduce your headaches in dealing with OS compatibility issues and Rockwell Software.