Snow layers with data value between 1 and 7 inclusive are shown as data value 0 in inventory

Seems to be intended. Data value 78:7 would hardly be distinguishable from snowblocks (ID 80) in inventories.

Well, Grassless Dirt looks identical to Dirt despite having a different behavior ...
At least, a different label for each data value would be nice.

You can see the damage values if you turn ID's on.

What ? How, Ezekiel ?

(Fn+)F3+H

Is this still a concern in the current Minecraft version 1.7.4 / Launcher version 1.3.8 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.