I've recently released a free WordPress theme with bbPress(2) skin called Skeleton. It is responsive, tested in IE 7/8/9, Firefox, Opera, and Webkit browsers, as well as all iPhone,iPad,and Droid devices. It also makes use of the Theme Options framework for customization.
You can see a demo here:
In effort to help keep users up to date, I'll be submitting Skeleton to the WordPress repository shortly.
Hope you find it useful :)
(Released under GPL)