Do you plan to create a cross-platform version of OS X's group buttons? These are cropping up in all kinds of desktop and web apps, so they've definitely left the realm of being a Mac-specific component.
I'm coding this myself, but it'd be nice if JIDE supported it.
Just so you know what I'm talking about, it's these kinds of buttons.
http://images.apple.com/ilife/imovie/im ... 070807.png