APP-V Versions

Dear,

We are currently running a proof of concept with APP-V through our MDOP agreement. We integrate with SCCM 2007 R2 SP1.
As a basis we started with "4.5 cummulative Update 1" from MDOP 2009.
This week Microsoft launched MDOP 2009 R2 that contains "4.5 SP1".

Can anyone describe the differences between both (in detail please).
What's the procedure to follow to eventually move from "4.5 cummulative Update 1" to "4.5 SP1" (both sequencer including already created virtual apps and the client).

Thanks in advance.

kind regards,
Alain VDP.