This all seems to be in line with the tanking philosophy Blizzard has been pushing for Wrath, one which Ghostcrawler recently reiterated: Blizzard wants to make sure that all tanks are as equal as possible. There should be no reason to take one class of tank over another, all things being equal, and no reason to sideline your tank because he or she is not the right class. Certainly, if this is to be realized completely, you do have to give every tank a good amount of AE capability, and this latest round of announced tank changes seems to be tailor made to do just that.
As the former player of a Druid tank and the future (current beta) player of a Death Knight tank, I'm very pleased to see these changes. I know that there was nothing more fun that running through a dungeon like Shattered Halls as a DPS with a Paladin Tank leading the way, and the idea that every tank class might be able to do that to some extent in Wrath makes me incredibly excited. It also allows groups to be more flexible in what DPS they take, including DPSers that traditionally have had a hard time getting groups due to having poor CC abilities, such as Cat Druids and Retribution Paladins.
If this change is handled right, it will go a long way toward solving the tank shortage for PuG groups, and, in fact, make the 5-man dungeon run fun again in general.