Since the DWF format has been gaining steam over the past couple of years, one of the requests I have seen a lot is for the ability to automatically create a DWF at the same time you save or close a drawing in AutoCAD. Starting with AutoCAD 2008, you can now do this. Read more about AutoCAD 2008 - Automatic DWF Publish
In previous AutoCAD versions, if you wanted to create a table that was linked to a spreadsheet, you had to either use an OLE link or use a 3rd party tool. New to 2008 is a "Data Link" feature. This almost certainly replaces OLE linked objects, and may or may not replace 3rd party tools.
Another new feature to AutoCAD 2008 is the ability to perform an inverted xclip. Inverted clip meaning that the data "inside" the area you select is clipped out as compared to an ordinary XCLIP where the data "outside" the selected area is clipped. Microstation has had this for a while, so it's good to see it finally added to AutoCAD. Read more about AutoCAD 2008 Xclip