As a WoW newb, you lost me.
What do you mean? Are you saying that this expansion is going to break with canon lore?
No... just it's going outside the somewhat constrained circle of lore built up through the three WarCraft games. WoW has generally stuck with things that have been touched on in the three original games. The Pardaren were first seen in... heck if I know, I think it was the WCIII expansion. It was apparently a little optional section, and had one Pandaran visiting wherever, not you visiting Pandaria. So they exist, but they have not really had any place in the story until now. As I put it at one point, 'it feels like the Hollywood sequel that shouldn't have been made'. Or maybe one of those Disney direct to home video sequels would be a better analogy.
You see, this is why I am grateful to be a casual MMO player. All these gameplay mechanics go right over my head.
Well, I'd bet you're very familiar with it all already. Most MMO's have the concept of 'classes', and a not entirely related concept of 'role' (damage, tank, healer). Many also have the idea of different 'skill trees' being related to each class, which often can help with one of the possible roles of that class (see
Rift for an extreme example of this, and D&D 3rd for a non-computer version of the skill tree—called 'feats'). WoW just calls them talents, and in some cases they just emphasize what aspect of the class you pay more attention to (e.g., Hunter), while others can shift you into a completely different role (e.g., Paladin).
Originally, WoW had a fairly open structure to how you did your talents.
Wrath of the Litch King generally designed it so that trying to generalize into two or three of the class talent trees was a
bad idea(tm).
Cataclysm forces this by locking you into one particular tree until you've spent the bulk of your maximum available points in it. The currently-proposed idea for
MoP is that you choose the equivalent of the old talent tree relatively early (level 20?), at which point all the old 'role-defining' abilities become part of the normal level/training progression. Then the more 'optional' or 'fun' abilities are the new talent system.
This is really part of the continued 'dumbing-down' that apparently happens to any aging MMO. In this case, Blizz's entire purpose with these changes is to keep players from making
bad choices. Of course, the ability to make bad choices is generally implicit in the ability to make a choice at all, and I'm just getting upset by the increasingly heavy-handed restraints being put in.