There's a pretty detailed breakdown available on some of the issues with packs from the affected models and years: https://skie.net/skynet/projects/tesla/view_post/23_Explaini...

Basically there are issues with the BMS that could cause an issue at higher states of charge. They shipped firmware to limit the charge until they could sort out the cause and potentially fix it with software. And it sounds like that part is resolved in many cases.

It looks like the charging issues are different, and he didn't go into those. Anecdotally, I've been hearing a lot of reports of that getting fixed too, though.