Image via CrunchBase
I was around just after Craig Walker and Vincent Paquet created and launched GrandCentral, which became post acquistion by Google, GoogleVoice. We worked with the two and helped make it a known qualtity, and to this day, my GV number is the number that makes me so easily reachable. But in over four years since Google snagged the service, not much has really happened on the services side, while most of the work has been done to keep it scaling and integrating into the Google way of doing things.
Basically, I have no complaints, as the service works. Every once in a while mobile calls sound bad, as latency seems to occur, especially when both parties are using Google Voice, but a lot of that is the carriers capacity issues, not GVs.
But one area they have not moved very quickly is being "open" and working with other services that could make GoogleVoice even more a part of more people's lives. Over at ZDNet, Jason Perlow has brought up faxing as a service he'd like to see. I know a few more, and if Google Voice did add them, I'd be able to eliminate a few other services.