I'm going to agree with you 100%. Word and PPT do not matter if the format changes a bit or whatnot (this already happens between different versions of Office). If you need to create a document that keeps perfect formatting, then you need to output in something like PDF.

Excel is a completely different beast that has so many features it's very hard to cover them all for all users. A big one we use is using Excel as the front end to MSAS. Normally we would have had to design some user/reporting interface, but instead we were able to use Excel pivot tables to access the data directly on the server. Since all of the analysts are already familiar with Excel and its pivot table interface I just had to show them how to to point it to our MSAS instance.

Warning: user perspective ahead:

I have to agree with this. I work as an analyst in an investment bank, and my tools include MsWord, Excel, PP and rarely a python script. MSWord and PP are completely interchangeable with they OO or google docs equivalents, but Excel is just another story, and its not just the learning curve, the software has a lot of features and capabilities that their competitors simply don't have (even for my less technically versed coworkers)

What I've found interesting recently is working a bit with a very non-technical user, and finding that after a bit of introduction, Google Docs word processor is actually easier for them to use than Word.

They don't need a ton of options and mostly just get confused by them. They just need some basic controls and good looking results, and Google Docs is beginning to realize this surprisingly well.

Plus, they never "lose their file".