Version 1.0

First time out While Microsoft has had some connectivity from its Office suite to other applications, mostly databases and the Web, none of those reached quite as deeply into the applications as these changes. It's a pretty heavy retrofit, and it's going to take a few versions to sort out the details.
Solutions seeking an audience It isn't entirely clear who's going to want these features. Microsoft itself can create tremendous momentum, but a lot of these features are aimed at power users (Excel) or integrators (Word, InfoPath), audiences whose need for these things is yet to be determined.
Unclear marketing While it isn't clear who will want these features, Microsoft has also limited the number of people who will have them as an option, and there are general concerns about interop between the Standard and Professional versions. Hopefully these concerns will evaporate before the products ship.