4 months from the day (3/29) the "Put the MBTA on Google Transit!!!" story hit The Globe (and the home page of Boston.com!), the MBTA has added their maps to Google Transit!
Despite the fact that the MBTA is not shown as a supported transit authority here (http://tinyurl.com/boey4m) or here (http://tinyurl.com/mqnt4d), if you type in directions, you can clearly use the option. The option is also available on my iPhone and I would assume all Blackberries and Android phones would have access as well.
Here's an example of directions from the Cambridge Innovation Center (http://www.cic.com) to the Boylston Street Apple Store, showing both Green and Red line trains and times.
It took a while but the goal was reached. The message was delivered to the "Put the MBTA on Google Transit" group in Facebook.