The following is a very quick list. See the Exploding Palm rune effects page for a more thorough summary of rune effects, or any of the individual rune pages for numbers, screenshots, blue quotes, and much more.
The first two strikes in the attack deal 100% weapon damage. The third strike causes the target to bleed for 65% of weapon damage per second for 3 seconds. If the target dies while bleeding, it explodes, dealing 30% of the target's maximum Life as physical damage to all other enemies nearby.
The third strike causes the target to burn for 78% weapon damage as Fire damage every second for 3 seconds. If the target dies while burning it explodes causing all nearby enemies to burn for 39% weapon damage as Fire damage for 2 seconds. This effect can chain repeatedly.
This was probably the coolest spell most people saw at BlizzCon 2009, just for the massive blood explosions it created. It was magnificently overpowered, working like an early D2C version of Corpse Explosion. Triggering the third stage of this one, then beating that monster down with 100 Fists, was almost certain to clear any room, killing every monster anywhere near melee range.
It will have to be nerfed in the final game since this is just insane for such a low level skill.
Combo skills are essential for Monks. Combos do bonus damage, grant special properties (i.e. lightning damage and interrupt attacks on Hands of Lightning), and build up the Spirit needed to cast other skills. All combos have three stages, each progressively more powerful and flashier.
Exploding Palm was first shown at BlizzCon 2009 as one of the originals when the Monk was unveiled. Flux was able to try it out:
This was probably the coolest spell most people saw at Blizzcon, just for the massive blood explosions it created. It was magnificently overpowered, working like an early D2C version of Corpse Explosion. Triggering the third stage of this one, then beating that monster down with 100 Fists, was almost certain to clear any room, killing every monster anywhere near melee range.
This skill was indeed moved from Tier 2 down to Tier 5 for BlizzCon 2010. Skill tiers were removed for the July 2011 Press Event, and Exploding Palm became a level 12 skill.
Fans have occasionally pointed out the oddity of this skill causing a huge, red-blooded explosion no matter what it's used on; bloodless skeletons, monsters with green or blue blood, etc. This issue was playfully addressed by Bashiok, the Diablo 3 community manager, in a forum post in April 2010. 
We have tons of unique death types, the exploding palm effect you’re talking about though is an effect of the skill itself though and not the makeup of the creature it’s used against.
When you apply the bleed-DoT from Exploding Palm a beating heart appears over the creature it’s applied to. After they take enough steps or are otherwise killed the heart explodes and deals AE damage. So it’s not actually the skeleton exploding (although that happens too) that’s causing the blood effect, but the skill itself.
...blood explosion is the AE damaging effect of the skill that occurs when the subject dies. It occurs along with the death effect of whatever it’s applied to, and isn’t an increase of their normal death effect.