The Weekly Standard's William Kristol doesn't think Romney will pick Walker, but he does think it tips the scales towards Romney selecting a governor to be his running mate.
The Romney camp may conclude that Scott Walker, his message and his spirit, are not part of the problem but rather part of the solution to Romney's electoral task (especially with working-class voters, including private-sector union members). After all, if Romney could hold 94 percent of Walker's vote from last night in November, he'd win Wisconsin, and the presidency.
So I'd expect to see more of the spirit of Scott Walker—and of Chris Christie, Bobby Jindal, Susana Martinez, Bob McDonnell, Mitch Daniels, or, if you want to go back a bit, Tim Pawlenty and Jeb Bush—in Romney's message over the next weeks. I'd expect to see Romney calling attention to successful Republican governance at the state level. I'd expect him to show up more with such figures in swing states.
And I'd expect one of them to be on the ticket. I could still make a case for a reformist senator (Pat Toomey, Marco Rubio, Kelly Ayotte, or perhaps Rob Portman) or congressman (Paul Ryan). But given that Team Romney would like to run against Washington, I think they'll be inclined to pick a governor. And given Romney's insistence on his VP being ready to be president, they'd presumably prefer a governor who's got some national experience or at least two terms as governor plus national exposure. So I suspect we may be heading toward a Romney-Daniels ticket...or, possibly, Romney-Bush or Romney-Pawlenty.