One of the main objectives of the CSSU is to get rid of Nokia binaries.
Nicola has already implemented the missing pieces for Control Panel and now is working on a Camera UI replacement. MohammadAG is working on a MEdia Player replacement too.
Let me direct you to this Wiki page with a rough status of in built applications.
That really depends on the "N950" success.
N810 CSSU flopped because N900 came out and sucked all devs. ;-)
Well hopefully the N950 wont be coming out till Q3/Q4 2011 so we can get some very nice updates for the N900.
Also if its running Harmattan it should be fully open sourced so all these other projects besides the CSSU will be compatible with the N950.
As long as the drivers are open sourced
Besides Nokia really blew it with the N900, alot of people have lost faith completely so I don't think many people are gonna jump ship and go straight to the N950 :P