For you CAISO watchers:

Some interesting info from Anjali Sheffrin's (Director, CAISO Department of 
Market Analysis) latest monthly report.  I cannot verify the data, but here's 
what she says:

Total underscheduling (% of load procured in R/T) is down from 10% in 
February to 6% in March and April.  Thus, CERS, seems to be actually 
performing its role of buying the net short position of the State before R/T.

Of all power bought in R/T, the large majority is (90% +) is purchased OOM 
rather than the through the hourly auction.

Of the OOM, approximately 95% is purchased by CERS.  By implication, IOUs are 
buying about 15% of the R/T power procured from ISO (100% of the non-OOM, and 
5% of the OOM).

The large majority of R/T is purchased from out-of-state resources.