Of course, all the above suggestions involve raster effects, therefore require rasterization, flattening, etc.

FreeHand has a somewhat cheezy, but all-vector, Emboss command that serves reasonably at modest sizes. These can be done in about 3 clicks:



As you can see from the insert, it's a blend-like stack, except that the intermediate steps are not sequential, but interleaved, which makes it a little more convincing.

So playing around, I hacked out a simple script <http://www.IllustrationETC.com/AIbuds/JET_X_InterleaveStack.zip> to do the re-stacking of a selection of objects in AI:



Applying Effect>RoundCorners, either before or after, with a "radius" of a few pixels improves it a bit, too (not shown).

JET