You might've already added these Aren (we're still on 3.0.5 ourselves, haven't been able to upgrade in a while) but this is some stuff we've found useful and added ourselves:
UIImage Button: added the option to set a disabled state sprite.
UIButton Color: added a disabled state colour.
UIPopupList: Added an option to adjust the speed of the TweenPosition and TweenColour.
UIPopupList: Added the option to offset the position of the popup box - to compensate for the sliced sprite bound.
UIToggle: Added a "Can be none" option when a toggle is part of a toggle group. For us, this was useful in avatar icon select - once a user had selected a picture, they weren't able to have no picture, so we added this to allow that.
UIInput: I think we added a custom validation type for Email. Not sure if it's clever enough to detect a bad email format, but it removes the illegal characters.
Minor things, but they were helpful!