the main reason i use android over iphone is the seamless integration of google voice, and gv already gives me access to my sms & vmail from the browser.

imho, the solution isn't to build yet another android app but to make google voice a natural/default choice for android users. if you have an android phone and haven't tried google voice yet, i highly recommend you give it a shot. having used it for the last few years, i can't imagine ever going back to carrier sms/vmail.