In all the hubub of late, I forgot to give mention to the fact that ComponentArt has released Web.UI 2.0, their new component suite. I've been working with this version for almost 6 weeks now, and I have to say that these guys really know how to do things right. Their stuff just keeps getting better all the time. They've completely re-written ASPnetMenu, which is now Menu 2.0 for ASP.NET, and it's really a pleasure to program against. The really awesome thing about it is, now you can nest User Controls as menu elements. It's wild some of the things you can accomplish now.
At any rate, I'm using all of their controls very heavily in a new project I'm working on, and I couldn't be happier with the result. If you need some high class navigation controls, forget Infragistics or ComponentOne. Check out ComponentArt instead.