The main feature we are working on for the upcoming Squish release is full-fledged BDD support built directly into Squish.
This includes everything from fully understanding Gherkin, the scripting framework to run BDD tests with step implementations in any of our supported script languages, full IDE support (skeleton generation, code completion, integrated debugging, integrated reporting, …) and advanced reports.
If you are interested to learn more about BDD in general, you can have a look at the slides of a talk I gave about this topic last week: http://www.slideshare.net/ReginaldStadlbauer/behavior-driven-gui-testing.