I'm not sure what they plan on doing with data values, but it's the block IDs/item IDs that are going to change. 1.7 is where they are deprecated, not exactly removed, so we can still use the blocks/items as they are, but at this point i'm not sure data values are going anywhere.
Anyways, should they change we'll just change along with them. I see no harm in messing around with them.
Added to redmine.