While I agree that your whole first paragraph is what made my DK so much fun to play, I think it's incorrect to label this as "lazy Blizz". Now before I get jumped on, let me announce that I am just as bummed out as everyone else, despite the fact I've been tanking in blood in every major content patch, and was hoping to see some neat way to make this work with the mastery system.

One of the prime reasons Blizz cited as why they decided to make this change is that it wasn't fair to all the other classes. Yes DKs are supposed to be special, but in the end it comes down to Dev Team resource management and fairness to everyone who doesn't play a DK.

On top of this, the new mastery system was the death of this lovely and enjoyable experiment to begin with. How does the system distinguish between tanking and dpsing? Tie it presence you say? Watch me spec completely for frost dps then hop into frost presence and we all go back to Wrath Beta, where DKs did the damage of rouges with the survivability of a prot warrior. Blizz worked so hard (to their credit, I think) to balance out DKs, and I don't want to see me getting my talent points refunded every patch in Cata due to major balancing issues.

Again, I was hoping this would be the future of hybrid classes as much as anyone else, but I think its fair to point out the massive logistical issues that would have plagued the system, and we shouldn't be too hasty to judge the Dev Team here until we see an actual 4.0 talent tree (remember, they're trying to get rid of "ideal" and "cookie-cutter" specs).