I found a nice Singularity paper that actually goes into some performance statistics..
Shows across the board Cycle reductions at the OS level for many systems within the SinguarlityOS.
I really want to see this Midori project's managed SingularityOS work (with dev platform) ... It really does sound exciting...
http://www.cs.rochester.edu/~sandhya/csc256/seminars/ryates_singularity.pdf
e.g. results
Software Isolated Process: Creation
============================
[Process create and start]
OS - Cycles
Singularity - 353,000
freeBSD 5.3 - 1,030,000
Linux 2.6.11 (Red Hat FC4) - 719,000
Windows XP (SP2) - 5,380,000
Software Isolated Process: Syscall
============================
[Minimum Kernel API Call]
OS - Cycles
Singularity - 91
freeBSD 5.3 - 878
Linux 2.6.11 (Red Hat FC4) - 437
Windows XP (SP2) - 627
etc. etc. (lots more stats in pdf above)