Here is a small image showing new items in Bryce 7 Pro. Its basically got some new lights, you can play more with the Render options and the instancing Lab. you also get Displacement and Anisotrophy in the material lab. If you use A mac like me Don't install Lion or Mountain Lion as they are incompatible With Bryce. To transfer Mats and Objects is simple either Save them in a lower version of Bryce preferably 5.5-6.3 and open it in Bryce 7 Pro and Save or make an obp and import that file into the create bar. And same process goes for the Mat import it from the Material Lab.

I hope this helps you

Karl