Can I use my WDW tickets at Disneyland or any other Disney park?
Yes and no. The only WDW passes that you can use are Park Hopper and Park Hopper Plus passes and even then only at Disneyland. You will have to take the ticket to Guest Relations at DL and they will have to call WDW Guest Relations to confirm that the ticket is still valid. There is a drawback though. When the PH gets converted, you will lose the ability to park hop at DL so you can only see Disneyland or Disney's California Adventure, not both in 1 day. You cannot use WDW AP/PAP's at Disneyland. None of the other Disney parks will accept admission media from any other park.