I've done my own research on the subject, but I want to see what others think.
I have a web application (intranet) that is currently written in ASP.NET 2.0. We're needing to update the UI so that we have more freedoms with it. (We are currently in the 10th circle of Table Hell). We are going to change from table based layouts to semantic layouts using CSS. Are there any new features, or any other benefits from using ASP.NET4.0 as opposed to 2.0 when targeting XHTML standards compliance for cross browser support?