Well in the future. I saw the widgets plugin from Wordpress and I am defeniately going to try to implement it into bbPortal. For plugins you'll have to be at the bbPress forum (www.bbpress.org). I don't think it's going to be a good idea to have some plugins here and some at bbPress, since bbPortal is a plugin for bbPress.
Widgets however arent in bbPress (and most likely wont be in it either), so those will be supported/ can be downloaded here. In the future that is!