MS have patented ribbon UI so it would be interesting to see if other developers get sued for implementing it.
I don't think they can do that. Last time I checked, Wikipedia says it's prior art, since a similar interface was used in Macromedia HomeSite or whatever it was called.
In addition, Microsoft is taking advantage of licenses: They don't want other office suites, regardless of license, to be publicly released with Ribbon, because "it will help you tap into the full potential of Office". No matter what MS intends on doing with that policy, it's an excellent but unfair decision-something that WordPerfect can't take advantage of, but will more likely screw Office users.
I've now installed OxygenOffice on my computer at work because I can't get used to the shitty ribbon UI. MS Office 2010 is supposed to be better but I don't see the point in paying more for what is probably only a bug fix for the shit UI.
Microsoft and their "innovative" GUIs.
The fan made "Copenhagen" concept for Windows 8 looks like it will need more clicks to achieve the same thing. It also bears a resemblance to Blackbox of *Nix fame.
If OOo is going to do a similar thing, I hope they make a decent job of it or do as AutoCAD have done and provide an option to revert back to the old UI.
At least with OpenOffice.org, you get to modify the GUI, if you're good at the OOP juggernauts C++ and Java.