At the risk of feeding the opposition, the opt-out is kind of a trick that favors the public option, with the purpose of giving conservadems some political cover next year and in 2012. The bottom line is that it will be very unpopular to opt-out of the public option.
A reader called my attention to this line in Ryan Grim's post about the Reid announcement:
Sen. Lamar Alexander, a Republican leader from Tennessee, said on the Senate floor Monday, in advance of Reid's announcement, that the opt-out provision isn't to be taken seriously. Medicaid, he noted, has an opt-out provision, but not one state has opted out. Public health insurance, in other words, is too popular for states to opt out.
There will certainly be a handful of GOP state politicians who will stomp their feet about opting out, but much like the recovery bill money they won't have the nards to literally walk away from it. And in a few years there will be town hall people shouting, "Keep your government hands off our public insurance policy!"