Am I missing something here? In the Beta 1 pack:
Microsoft.Hpc.Scheduler.Session.dll had File Version 3.0.2021.0, Assembly Version 18.104.22.168
In the RC1 Pack:
Microsoft.Hpc.Scheduler.Session.dll has File Version 3.0.2328.0, Assembly Version 22.214.171.124
That change to the assembly version was actually made back in Beta 2 to improve backwards compatability with previously-released applications designed against HPC Pack 2008.
(Beta 1 was ~Oct 09, Beta 2 was ~March 10)