[netghost]

This one doesn't have a dependency on jQuery if that's a selling point for you. There is also an option to wait for mouse / keyboard input before dismissing, which is kind of nice as well.

Otherwise it seems similar to most of the others.

[wavded]

I would also add mobile webkit support, and ability to create themes with Stylus (which renders IE gradient fallbacks, easy vendor prefixing, etc). I'm not sure if the landscape has changed much but I haven't seen many that support CSS transitions. At the end of the day its just a fun experiment that some people may like and other may not :)