I'm just going to show you some comparisons.
AT LAUNCH
BC = 10 levels
Wrath = 10 levels
Cata = 5
BC = 12 dungeons
Wrath = 12 dungeons
Cata = 8
BC = 24 raid bosses (12 kara/4 eye/6 serp cavern/1 mag/1 gruul)
Wrath = 17 raid bosses (15 naxx/1 sarth/1 maly)
Cata = 12 ( Blue post just stated that Bastion of Light raid will have 6, and that they plan to have roughly 12 total at launch between Firelands and Skywall, one of these instances will likely contain a single boss.)
Point made here: Blizzard's "most end game content expansion to date", which has been marketed as such, is quite inferior in dungeon and raid content to its previous expansions.
BC = Jewelcrafting
Wrath = Inscription
Cata = A profession that we now know as of yesterday will not directly benefit your char in any way; you find lore excerpts and collect rare and logistically useless artifacts. Archeology
Path of Titans: gone
Guild Progression System: watered down, practically drowned as of yesterday, suspect at the very least imo.
Medium Glyphs? Go look at Minor Glyphs again and explain to me again how Medium Glyphs aren't essentially an acute extension of Minor Glyphs. They could have done this in half a patch but they're going to push it as a major feature now, frankly because they've got nothing left to go on.
3000 new quests? Guys, there is a damn good reason they will not tell us how many of those quests begin at level 80. 2000 of those quests are reserved for the countless lower level regions and questlines that they retrofitted to coincide with current lore. I bet you 39.99 that Cata has less quests from 80-85 than Wrath had from 70 - 80. It wouldn't be a wise bet to take.
So what are we gettin for 40 bucks? 2 new races and flying mounts in a marginally reconstructed Azeroth. I appreciate the effort from Blizz, very sneaky, but they can no longer hide that they tried marketing Cata as a quick start raid expansion, and folks, it ain't.
I've played (strolled around) the alpha, it's pretty. The question is: is it pretty enough for you to appreciate it after you kill the only 12 bosses within 2 weeks of launch, waiting 4 - 6 months until Blackwing Decent and War of the Ancients comes out?
Don't let them fool you, this will be, at least initially, the most underwhelming expansion to date.
P.S. No need to reply with "then don't buy it, don't play it." That's not the point and you know it.