Google Voice was a hugely exciting service when it launched a few years back, but it seems like Google has put it on the back burner recently. Maybe things are picking up, though. Just last week Google announced that Voice was finally adding support for MMS, and now there's more news on that front. T-Mobile has opted to allow MMS messages sent from its users to be delivered to Google Voice numbers (sort of).
It's similar to the functionality already live on Sprint. If a T-Mobile users sends an MMS to a Google Voice number, it will display the image in the Voice user's Gmail with an optional SMS notification. Yeah, not the most elegant solution, but it's better than nothing.
Google is continuing to improve support for MMS into both Voice and Hangouts. It seems a strange throwback feature for Google to be worried about, but some folks still demand MMS.