It what is probably the least shocking development of the holidays, Microsoft's announced support of ODF in MS Office 2007 SP2 will not be interoperable with other implementations of the standard.
Microsoft has announced that ODF will be implemented in Office 2007 SP2, due out between February and March of 2009. Under MS's Document Interoperability Initiative (DII), a preview of the implementation strategy has been released, but it varies significantly from other suite's current implementation of the standard, ODF Alliance Managing Director Marino Marcich said in an interview with PCWorld. He claims that MS's course will break interoperability.
I feel like I should be writing for BoycottNovell now, but I can honestly say that very few people I've talked to over the last year expected MS to do anything different than the announced plan. Most of us expected MS's ODF to behave in strange ways that would break any chance for other office suites to get a fair shake.
MS's OOXML doesn't meet the specs and is thus a lock-in. MS's ODF is intentionally breaking interoperability, giving people the impression that either the standard or the other office suites are sub-standard. It appears not as much has changed in Redmond as what many tech writers would have you believe.
Business as usual at MS.