Styles rounded corners & browser compatability
 

It's nice to see rounded corners being used in VB 4, but it's let down badly by the fact they don't work in IE (8 and maybe other browsers I haven't tested yet). I use malsup jquery corner on my sites. It's mind numbingly easy to use, very versatile, many styles, image-less (pure js) and is supported by all the major browsers.

If you are going to implement these sorts of features, which I think you should, they should be cross browser compatable or left out all together!