Part of what I see is that Google does not have a good model for making Google Voice profitable given their revenue model because it doesn't drive eyeballs to Google search and the advertising customer base, and because datamining the communications of Google Voice's users for the sort of keywords and profiles useful for search has a huge potential for social blowback - imagine how some people would react to web page ad placement based on last night's booty call - not to mention the possible legal problems given the diversity of wiretap laws, e.g. state by state in the U.S. never mind world wide variations.

[Edit] Given changes in Google's leadership and the apparent emphasis on core function which seems to be underway along with the limited rollout which Google has done for Voice, I would not be surprised if it is destined for the same fate as Google Health over the next few years.