Tossing up a few useful links and a few random comments to go along with it.
How do I send in bug reports ? Apple bug reporting works very good, and they are responsive.
It seems like Microsoft tries to avoid bug reports, as that means work on old products, instead of trying to catch up.
I just installed Office 2011 for mac, and was hit by the mdworker32 consuming 100% of 1 core caused by Microsoft Office.mdimporter not being able to read xlsb formatted files. Had to delete the mdimporter, and lose spotlight indexing of my office documents.
This is a pretty old bug that you have carried forward to Office Mac 2011, instead of fixing it, or dropping the import filter altogether.