Hah. I'm sorry my friend but you clearly lack the understanding of game design to comment on what takes time and what doesn't and that's from a level designer. You have to understand first and foremost that everything you think is easy -even if it is relatively easy- will take several work days minimum and that's not including internal QA. (That's Quality Assurance/Assesment for someone who obviously has no idea how the game industry works.)
That Maelstrom fight? Easy? Do you not understand that they probably had to rebuild that whole set and more to make that fight work? Dragonblight was re-used heavily in this patch and I'll give it to you that it was lazier than they could have been but it does fit. That's where Wyrmrest Temple is, that's his rightful throne of power moreso than anywhere else.
As designers they re-use as much as possible as often as possible because time literally equals money so re-using textures and models (and other assets) and editing them slightly is more cost efficient than making a new one from scratch. It makes no sense to create a new model, costing lots of money and time thus delaying the patch, for a Twilight Dragon when they've long establish what the Twilight Dragons look like. Edit the Alpha, the colours, the textures slightly and you're done there.
You also don't seem to understand how encounter design works. Coming up with the bare basic mechanics of the fight takes a few hours. That's roughly 5% of the work done, GG. AI programming, sound bite recording, spell balancing and more. All this will go through hours of testing and will be bounced from programmer to developer several times so tanks don't get one shot by two overlapping mechanics etc. ala your precious Burning Crusade where big raids were released with several encounter broken beyond completionand you just had to make do with "RNG Fights" as you called them where sometimes you Tank regardless of skill or gear would just take a nut cleaving 20k damage and die instantly.
You're biggest problem with this raid appears to be with the re-use of old assets though. I already mentioned hopefully enough points to explain to you why you're ignorant but let's use your examples. You seem to revere Icerown Citadel as the example of how a "final raid" should be done. Did Icecrown use unique models? Marrowgar, yes. That's it. Blood Queen and her ilk were MAYBE unique models but they were fundamentally just edited Blood Elf or Night Elf models. The important difference is the texture changes. Even the last boss was a model they'd used repeatedly -nay, excessively- throughout the expansion. Admitedly they did use some models like Putricide that hadn't been used that much beforehand. Dragon Soul bears no lesser or greater quality than anything before it. If you think you can do better then do what I'm doing and join another MMO company and see if you can do any better. Become a game artist and try to never re-use assets and not get your ass fired.
This ^^ pretty much perfectly sums up how little of the process you actually understand. You can't just "copy and paste" stuff like this. As you yourself conceeded there are new animations, those are one of the most labourious jobs involved with the process of setting these things up and every model will have to go through it's own animation process, not even just the ones with new models. The movement of bones of the skeleton on a model at one size doesn't neccesarily scale up like you'd expect it to - check this video for an example of that in another game:
http://www.youtube.com/watch?v=8ZDgj...eature=related
There is so much more that you're wrong about but you're just a spec on the internet and I can't really be bothered to correct you so hopefully you can just take what I've said at face value and trust me on it. Dragon Soul is fine. If you no likey then it's not because Blizzard has dropped the ball, it's because your standards are too high or because you just don't like WoW anymore and are looking for problems, in which case it's time to leave the game and it's forums.
Good luck, have fun.