I'd have to agree with medscape WRT the President going to the affected areas. While it may (or may not) be politically prudent to give face time in the area, it would be a logistic nightmare. How many police officers does San Diego or LA have available to support the President's presence.
He should, and probably will make a statement within a day or two, regarding the causes of the fire, but not yet.
I do agree that Arnold should be in the area as well, and I would hope that the media aren't just ignoring him (as they ignored the fires all weekend).