How many states would Opt-Out of a federal PO?

[Kurt_and_Hunter]

Poll question: How many states would Opt-Out of a federal PO?

In reading about the (vague so far) state opt-out compromise idea it seems that much of ones view of the idea is determined by a sense of how many states would opt out.

In general, the more you think would opt out the worse the idea. Even folks who like the idea vary a little... Paul Krugman's first blush is that some small red states might opt out. Nate Silver offers good reasons for thinking it would be unusual for a state to opt out, but allows the possibility. I don't think any state would opt out because state politics is more $$$ oriented and opt-out is proactive... you have to cast a vote to deny people.

Based on what little we know, what is your estimate of how many state legislatures would actually act to opt-out?