I don't think we'd be likely to do away with SBV. I could see doing away with block rating.
It is good for itemization to have some stats which are very defensive oriented. SBV does have some offensive potential and it does play well with Strength so it already is more versatile than say something like armor.
Getting rid of block rating would be a big change and would require us to mess with several items and talents. (Read: this is probably not in the 3.1 time frame.) Ideally though, we think there might be a place for block that is in between say the guaranteed mitigation offered by armor and the RNG mitigation offered by avoidance.
It might be tricky in that world to differentiate paladin and warrior blocking, and maybe we wouldn't need to. Traditionally, the paladin blocked every hit for a small amount and the warrior blocked fewer hits for a larger amount. In reality, I'm not sure that niche buys us much except for paladins being able to tank 10,000 adds without taking damage.
