Major changes and/or clarifications that are effective immediately
1) Trainer Pokemon now have all level up moves and BW TM's, as well as an unlocked Dream World ability, so they can compete with better Pokemon without demoloshing undertrained ones. These are things like Wingull and Tentacool people. They aren't overpowering.
2) Agressiveness now has an application towards switch=ko/ok. If you choose to use the flee command to escape a wild battle, the Pokemon will have an RNG rolled based on agressiveness. If he succeeds in stopping your flight, he gets a free round in.
You may always withdraw a Pokemon when ordering against a wild Pokemon. However, if you do so a similar RNG will be rolled. If it fails, the Pokemon will get a free attacking action to stop the pursuit, but it must be an attack aimed at a Pokemon withdrawing. If multiple Pokemon are withdrawing or multiple trainers are fleeing, the Pokemon can only block one max, which will be determined by RNG.
3) Double critical hit. Yeah, if a Pokemon rolls a 625 or less with an attack, and then does so again, it's an automatic death. This is to simulate really powerful crits (deathly weak points) that wouldn't really be survivable.
4) Crit moment revisions: They now only have a 20% chance of occuring. However, you can also get a Moment of Fate (4%) that will have two uncertain outcomes, although one will be much safer than the other, but have a lower reward.
5) Withdrawing a Pokemon from ASM to ASB. If a Pokemon caught in ASM is in a PC Box, you may use a PC to beam it out of ASM into ASB. While it will no longer be usable in ASM, it will become legal in ASB at the end of the day. This had already been posted, but I wished to clarify.