They don't want blood per se, but rather they want to end the geopolitical uncertainty. And the way they do this is by setting up the game theory so that it's in everyone's rational interest for the situation to resolve itself in a way that benefits the US and minimizes global risk. And if this means a few hundred protestors getting killed, that's what's going to happen.
It's not really different than any other coup or revolution.
There are people who fear the Egyptian electorate and want to discredit the protesters. Those people are hoping it gets as violent as possible so the television footage scares Americans and prejudices us against any government in Egypt that represents the people. I'm sure there are many individual CIA agents who share that bias.
That said, I imagine the leadership of the CIA has better sense.
Certainly it's not proof, but I'd be surprised if the CIA wasn't involved. Their main goal is to minimize the uncertainty of the situation, so if they saw a play to both end the uncertainty and also have the situation resolve on US-friendly terms then it would be surprising if they didn't intervene. At the very least they are strongly encouraging the situation.
