Updated my site to RC3 last night and noticed a few issues. I don't know whether they are specific to RC3, or whether its just a case of I was carefully looking out for problems at that specific moment:
1. Embedded images in forum posts have all been made thumbnails.
2 Before logging on, members who uploaded their own avatars are seeing the initialled avatars by default not their own avatars.
3. Oddities when inserting a table into a post. If you type text, then select a table and multiple rows, say 20, to go into the table, the text is either moved below the table or deleted.