Windows Mobile devices all offer Pocket Word and Excel so I think Apple is missing a trick here in promoting their own product.
I have mixed feelings about that... it'd be nice to have basic ability to view Word/Excel/PPT attachments (particularly Word and PPT, and of course PDF), but at the same time, I think it's worth it to remember how much better Apple does with the market than those Windows Mobile devices. Of the two strongest smartphone companies at this point, at least in North America (RIM and Apple), neither of them really stress these kinds of features, and yet, particularly in the case of RIM, they have consistently for some time dominated the market.