Office 2007: A Bad Idea Gone Bad
A couple of months ago my employer began the process of deploying Office 2007. I had done a bit of playing around with Office 2007 prior to moving to it on my primary laptop, and nothing I had seen impressed me. Now that I've been working in Office 2007 for 3 months I can safely say there is nothing to be impressed about: Office 2007 continues Microsoft's tradition of allowing new grads and coop students to write and publish production software under the guise of responsible, mature software development.
Others have written about the problems with Microsoft's XML file format; so, I will not dwell upon them except to note that file reads and writes now take longer (that is, they are slower).
The primary "problem" with Office 2007 is its user interface; specifically, with what Microsoft calls the "Ribbon". The Ribbon's problems are numerous, but other user interface changes lurk in the dark that impede the progress of any but occasional Office users.
Microsoft's Office 2007 UI architects have argued publically that the new UI enhanced end user productivity; however, this assertion is not borne out by any empirical measurement: as I've noted above, any such measurement shows the opposite effect. I will admit that if you have never before used Office then your first few minutes with Office 2007 will be more productive; however, after the first few hours Office 2007's new UI will simply get in the way and slow you down.