I can understand the arguments against storing all of this data on the Google-provided services. But after having used the phone for a while I can say that it is one of the strongest selling points. Particularly the calendar and contacts. Rather than requiring some Windows-only (or, if they're feeling particularly magnanimous, Mac OS X) software for synchronizing my contacts between the phone and a single computer, I can import them into Gmail from my workstation and they quickly show up on the phone. Linux support out of the box.
With previous phones I had a "choice" of using Windows to get properly sync'd services or having the phone be the sole repository of a good amount of personally important data.