Transformers Universe might be the game you've been waiting for.
The browser-based title, developed by Jagex with a little help from Hasbro Gaming, is currently slated for release in 2013. And while we still have no official launch date, comments by the Hasbro brand team at this year's Botcon 2013 have narrowed the release window down just a touch, confirming that the game is due this fall.
Jagex has kept the game mostly under lock and key, but you can catch a glimpse of it by registering for closed beta and hoping the key-gods show you favor.
[Thanks to Max for the tip!]