Christian said:
Uh, yeah, synergy bonuses. That's what I meant.
Figured you meant that

.
As for cleave, keep in mind that you can cleave with a blunt weapon, and a cloven opponent can still survive the battle. You're not chopping someone in half -- rather, you're seeing that they've gone down, and without pausing whirling and twisting and attacking someone else.
I'd say that, If and Only If someone believes that they succeeded in dropping their foe, their cleave reflexes can kick in and they can hit someone else.
However, that's a bit of a houserule. A rules-nazi will look at the cleave feat description and rule that cleave only kicks in when an opponent is ACTUALLY dropped, not simply when the cleaver BELIEVES an opponent is dropped.
One more rules-nazi problem with this strategy: bluffing is something you've got to do, and normally you've got to do it on your own turn. This means that your enemy would hit you, you'd remain standing, and then when your turn came up, you'd fall to the ground still. If your DM is strict about the rules, this is a highly unbelievable bluff to make.
However, the DMG points out that there are some circumstances under which you've got to fudge turns in order to reflect the simultaneity of folks' actions in combat. I'd argue that this is one of those times. If somebody wants to pretend that their enemy's blow just dropped them, I'd allow them to immediately move their initiative to just after the enemy's initiative, with the caveat that they MUST spend their next action doing nothing besides pretending to be dead. (essentially, their initiative order moves up, but they lose a turn).
Daniel