Shift clicking a minecart with a hopper/chest still opens GUI

Confirmed, but what do you expect what shall happen when you shift-click the minecart ?
The intent of shift clicking blocks with container is to place other blocks like torches and so.

Minecarts, including those containing other blocks such as chests, furnaces, hoppers, etc. are actually entities, and not blocks. Shift-right-clicking only prevents the GUI from opening on blocks, so that you can attach blocks to things like chests. Because a minecart is an entity, and can move freely, you can't attach blocks to it – blocks can only exist on the 1-meter grid, and never in between two grid spots. Falling blocks, such as sand, gravel, and the anvil, cheat that rule by temporarily changing into entities while they are falling, during which time they do not function as blocks.

Shift-clicking is also nice if you want to eat food while looking at something with a GUI.

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

Still a concern in 1.7.5 and 14w08a

Shift-clicking only suppresses on blocks.

@Grum: False. When you shift-click a mob, you have a monster egg of that mob.

That's only if your pick block button is shift...

edit: Or something like that.