To some extent, Warriors have fought like this for quite awhile. Shield Bash, Shield Slam, things like that. It wasn't just Shield Block. However, none of that stuff hit very hard. Sure, Protection Warriors shouldn't be able to rock the DPS with their shield, but Shield Slam was more like Shield Bump. The higher block values and thus higher Shield Slam damage is exciting, and the addition of Sword and Board puts even more emphasis on the shield.
Protection Paladins get some of this, too. It's not just about blocking via Holy Shield. The Burning Crusade added Avenger's Shield, and Wrath of the Lich King is taking it farther with Shield of Righteousness. At least to me, this seems like a fun direction. When I'm tanking, I don't like to envision my Paladin huddled behind their shield and occasionally poking their sword out at something with their eyes squeezed shut. I want to go in there and bash heads, and barrel things over with my shield.
I much prefer thinking of my shield as another weapon, and I'm glad to see that's being explored further by the devs.