In this question it was suggested that possibly SquareSpace would support twitter bootstrap as a front-end foundation instead of YUI:
http://answers.squarespace.com/questions/6041/how-do-i-create-a-squarespace-template-using-bootstrap.
I've tested the waters of the developers API for my site but without full Twitter Bootstrap support I'm just not ready to take the leap... is that support still on the table? Any timeframe?