After working on a few AAA games, I'm a firm believer that game UI should be created by artists and designers using proven animation tools like Flash, Maya, Max, and Silverlight. Just about all the studios I know are using Scaleform to create rich professionally animated Flash UI. While others are still implementing their own solution in Maya and Max, which can give you cool 3D effects, but I assume Flash will add those soon too. Just my .2 cents.