Can anybody recommend me about good resources to find out about new feature, planning, preparing and upgrading to MeetingPlace 7.x?
I don't think there is a technical upgrade path from 6 to 7. With MP 7 the 8100 chassis goes away and you have to replace your audio blades in your 3545 or completely replace your MCU(s) if you are using 3515s. If you have SASU/UCSS/whatever you will get upgraded licensing but I am pretty sure you will have to buy new hardware.
With the architecture change Cisco actually made things much simpler but it is really going to inconvenience people that have a MP5 or MP6 installation. I would think they would offer some sort of upgrade program where you can give them your old 8100 and get a new MCU to support MP7 but I haven't heard of such a program.
Let me know if any details are still fuzzy.