It's not really their fault, though - unless you're referring to CCleaner. Everything should work fine until CCleaner deletes the uninstall/rollback files.
Could you clarify the definition of "installed as hotfixes"? I think the confusion here is that CCleaner was (is?) deleting "%windir%\$NTUninstall*$" - that is not the definition of a hotfix, really - that's just an uninstall/restore folder naming convention. If you break apart an update.exe package, you can see how this is all set up, and the folder naming and folder deletion here is fairly arbitrary on both sides (MS and CCleaner). There's nothing fundamentally wrong with what MS is doing - the CCleaner analysis of what constituted a hotfix restore folder needed to be tightened. I'm interested in knowing what the specifics of the new change are.
That's not particularly true. WMP11 offers two uninstall routes - the standard Update.exe restore, and a System Restore entry point. If you stomp on one, you should have the other unless you have also stomped on or turned that off too. I'm not sure what else you would want here - two methods is usually one method more than any other applications offer.
There's a minor change or two pending on this area that will show up in a later build of WMP11 than you have now that will make things easier. But the absolute critical thing here is that we all need CCleaner to not delete the WMP11 restore files. I can "fix" this on my side by doing something a little non-standard, but it's really sad. I'm here to see what the CCleaner fix is and what can be done to ensure that everybody has the best possible solution here.
I work (at MS) on the code in question here, and find this area fairly fascinating. I definitely want uninstall/rollback/restore to work for people. If the restore files are not deleted by CCleaner, this all should work fine. If not, that is a bug that should be fixed by the WMP team - if you post details at microsoft.public.windowsmedia.player , I'll generally take a look at it there (please bear in mind that I also have a bunch of development work to do, so can never respond instantly nor offer personal support) and see what data I can glean from uninstall failure reports. But if you're run the old version of CCleaner that deleted the WMP restore files, you pretty much are limited to System Restore as a rollback/restore method for your previous version. Or, as suggested elsewhere in regards to IE7b2, you can copy someone else's restore files and hope.