Microsoft Mac development
About the "personnel reshuffling within Microsoft's Macintosh Business Unit" description. Makes me imagine people shuffling along to some other company.
At one point Microsoft did write some really good software on the Mac, including their Outlook Express 5 which was one of the best email clients I'd used on any platform (personally didn't even remotely like Apple's until OS X 10.4, the first time I decided it was usable)
Today's "Outlook" for Mac seems to have strong ties to Entourage, which started off fairly disastrously (in my experiences) and still has some of the original bugs, particularly connectivity. It even misses out certain features Microsoft implemented in Outlook 2003 on Windows (e.g. polls/voting, which personally I don't think should have been part of Outlook but there you go).
As for interoperability, some of the blame can I think laid at the docx/xlsx etc formats. I remember seeing a document pass from Mac to PC (or vice versa, can't remember) and on the receiving machine where background colours had been chosen (from the default palette no less) both the yellow and green turned into a single colour, and on saving stayed that way even when sent back.
I don't even want to start thinking about the UI on Mac Office 2011, a bizarre mix of menu bars (forced by the OS), toolbars and "ribbon" elements (and I personally hate ribbon UIs).
OpenOffice.org, NeoOffice, LibreOffice, take your pick and add Apple's Mail and Calendar and I'd say you don't need anything from Redmond's suite.