When items are inside blocks they used to move upwards.
This was changed (probably related to the changes for MC-73302) in the recent snapshot.

Steps to reproduce
1. Build up a 3x3 out of some full block on the floor.
2. Punch out the center block.
3. Throw an item in. Looks like this now: 2015-09-16_18.04.47.png
4. Place the block in the center again. 2015-09-16_18.04.54.png
5. The item does not move up as it used to.

Why is this an issue?
As mentioned on MC-73302, item elevators are widely used among players. While I understand why test137E29's fence item elevator got fixed along with the bug, I think that it would make sense to keep the feature of moving items inside blocks upwards to allow for item elevators in general.
Also just imagine a situation where TNT blows up sand. The items dropped would be stuck inside the blocks that fall down from on top. It would be nicer if the items would find their way to the surface.

An alternative idea
What also could also be done to enable easier item elevation would be to make items able to get flushed up half blocks.
Basically just setting their step height to 0.6.
I know this is an entirely different feature request, but it is related to the issue people have with this change.