Not that I'm aware of! Trello is pretty tight-lipped about their development process and what features they're working on. However, that doesn't mean there isn't a way to get a general idea of what they might be working on.
If you look at the Trello Developer Forum, you can see a list of features that have been requested by users. This isn't an official roadmap, but it does give you a general idea of what users are hoping to see in future versions of Trello.
If you're really interested in what might be coming down the pipeline for Trello, your best bet is to keep an eye on the Developer Forum and see what features are being requested the most. With any luck, Trello will eventually add the features that users are requesting the most!