When it comes to Classic, Blizzard's goal is to provide an authentic Vanilla experience, but they also needed to come up with technology to handle many players at launch, which is similar to sharding. While the use of this technology will be limited to the first month following launch, many players are questioning this decision and wouldn't like to see layering in the game at all.
I consider myself a purist in that I would prefer classic to be released as close as possible to the original. Where that is on the spectrum of patch content will be up to blizz. I'm also not vane enough to believe that any single state of the game is the "Ideal" location we should be aiming for. There is common ground that we can agree on, and I would welcome more than a few changes as long as they are made in the spirit of keeping classic on the vanilla rails.
Apparently a lot of the current World of Warcraft Classic closed beta testers are reporting things as bug that, well, simply aren't. There are enough of them, in fact, that Kalvax, the Classic community manager, posted a lengthy "Not a Bug" list on the forums. Some of the things that are actual features in the game include Tauren melee reach and hitboxes are larger than other races, Warrior health regen is working as intended and creature respawn rates are "much slower".