I know that this thread was from a lot of years ago, but I was feeling in an irritable mood after yet again having to click-click-click my way just to change to a new window in Excel. (And Alt-Tab is not a solution; I have a LOT of windows open constantly and having to shuffle through every window of every application that I have open is nowhere near as convenient, when it comes to switching between the three workbooks that I might have open, as an always-present drop-down list as we had in the 2003 era. Nor is moving the mouse alllll the way to the bottom and trying to pluck out the window that relates to the workbook that I want to move to, especially when it's simultaneously cluttered with unrelated (IMHO) windows like the VBE or a number of non-modal pop-ups. Yes, the VBE is part of Excel but if I want to move to the VBE then it's not the same as wanting to move to another worksheet.)
I did a search to see how many others felt similarly, and one of the search results that was returned was GregMac's post.
However. I will give MS one point with regard to the abomination that is the ribbon and it's this; in 2010 at least, you can add the switch windows drop down to the Quick Access Toolbar. I still don't find it as intuitive as the old View menu since it's alllll the way over on the left which generally means, as a right hander, dragging the mouse across most of the screen. But at least it's there. This may help someone who has been similarly irritated and wants a workaround.
But the thing that really annoys me (other than people who state that the only people who hate the ribbon are ones who are not open to change, whereas the reality that many think, with valid reasons, that it's simply a bad design) is the way MS preserved their own keyboard shortcuts but said "screw you" to those who created their own tools and add-ins. In Word 2003 I had a toolbar which had all of my most common commands, accessible by keyboard shortcuts. It was a HUGE productivity booster. But now, the former toolbar sits on a tab where yes, I can still point to it and click my mouse on it, but can no longer access all of those commands, many of which call custom VBA procedures, without lifting my hand from the keyboard.
Or take another Excel add-in that I use. To open its main dialog in Excel 2003, it's [Alt]  [S]. Bingo, done and dusted. And since the "1" is part of the add-in's name and the S is the first letter of the name of the dialog that opens, it's totally intuitive. In 2010? Alt+ [Shift] +  (to give [Alt] + [!]) followed by Y3. Yeah, that makes life just so much easier. But hey, the original keyboard shortcuts weren't native Microsoft ones, so they can't be important. And in any case who wants to use a keyboard when you can return to the salad days of being a 3 year old and moving your hand back and forth to a mouse so that you can click on big, chunky, brightly coloured icons just like you used to with Fisher Price toys?
It's great that the world is returning to pre-literacy with icons that you can point to and swoosh and swipe, but I can't help feeling that perhaps, just possibly, a GUI which requires more time moving to and from the mouse, which sweeps away 20 years of experience with a single blow, and which in 2007 was almost completely un-customisable and is only slightly better now (again, where are the THIRD PARTY-DEFINED keyboard shortcuts)... well, let's just say that I don't see it providing huge leaps in productivity when it comes to doing serious work rather than watching kitten videos on You Tube. I'm not saying that all-brightly-coloured-icons-all-the-time-no-words-needed tablets and phones don't have a place, I just don't think that office applications are it.