Once things start to settle down and people start actually using the software I'll probably start blogging on how to sue some of the features. In the mean time if you need your "tech fix" on the new releases here are some great blogs to find out more information on the latest for ACAD 2015 new releases. Autodesk's Shaan Hurley has a great list of blogs: Between the Lines
For Revit 2015 I think we can expect features such as the ability to do "sketch lines" (actually I can confirm this feature as I've seen it already) which will be great for presentations, both in 2 or 3D. Linking IFC's and the better display of IFC geometry. Improved scheduling capabilities in Revit. Improved revision clouding and improved energy modeling...
But I'm just speculating... we will find out early to mid April...stay tuned.
I dont thing there are going to be any "Earth Shattering" new features but just consistent improvements on the previous version.