Vodafone recently hinted in an interview that though they'll be developing more Android devices, those upcoming Android devices may be less Google-centric than the current Android phones available (namely, the Magic and the G1). According to Vodafone's Rachel Williams:
While the HTC Magic contains all the Google features we've come to expect tightly integrated, like Google Mail, future offerings might be more of a 'basic' package, where networks will want to put their own clients on there instead.
We examined the Android vs Google phenomenon in a previous article and it's beginning to look like this Android-centric or Google-centric tug-of-war will become an issue as the Android platform grows. And though Google's integration with Android is best-in-class, the fact of the matter is, not everyone needs to be tied down to Google clients--carrier's may be more interested in developing Android sans Google.
So perhaps our initial hypothesis of why there isn't as many Android devices is true: Google wanted a period of "exclusivity" with their own OS to build the brand name up and phone manufacturers wanted to create their own imprint with Android.
Only time will show how far Android can grow with or without Google. What do you guys think?