So Arnolds in after all. I imagine that California Democrats are filling their BVDs about now (as I write it is 8:30 p.m. California time). Arnold timed this entrance exquisitely, waiting for the Democratic strategy (close ranks around Davis; Feinstein stays out) to gel, and then scrambling their calculations with only 72 hours to go before the filing deadline.
I suspect this will increase the pressure on Feinstein to enter the race. I rate the chances at better than 75 percent that she will now be in the race come Friday night.