This info was accurate at 10:30pm, but none of my posts went through while I was still at the park.
I don't have the most up-to-date info about if they are letting people in to Disneyland, but there are LOTS of people leaving (but lots of people coming in too). The line to get through the security checkpoint was all the way back to the fountain. There was no line to get on the parking tram from the Structure. When we got off the tram, the tram operator said they were letting people back into the park.
However, southbound I-5 is jammed all the way back to Brookhurst, especially the right lanes and the carpool lane. Access to the Mickey and Friends Structure is gridlocked on surface streets. Northbound Disneyland Dr is jammed from Ball Rd to Downtown Disney. Some levels of the M&F Structure are gridlocked with people trying to come and and other people trying to get out. Levels 3 and 4 are especially bad, and their exits are jammed because you can't get to the Express Lane overpass.
I think Disney really underestimated the popularity of today. They were saying earlier in the day that it wouldn't get this crowded, and even when it did get crowded, they didn't have cast members in the walkways helping move the people efficiently. Oh well... it was still fun!
Good luck everyone!!