The DK is already a very strong tank. With or without these changes, they're very much a strong contender for best boxer tank.

The only situation I've found that sucks for a DK tank, is when silenced.
Other then right-click auto attack, most of the moves required not being silenced.
In particular, doing Stratholme as a mid 60's, being silenced really sucked there.

In every other situation, the class has rocked. They've easily solo'd Burning Crusade era group content, which none of my other toons could do as easily.
The class is fine.