A major problem I see for Obama in Pennsylvania is that it is a closed Democratic Primary -- no independents allowed. That cuts off an important part of his coalition. Hillary is stronger among self-identified Democrats. Given that the demographics of the state favor her and the Gov. Rendell will be running his machine for her she has to feel good about her chances. Whatever happens with the state delegate count, a strong victory in a key state like Pennsylvania will definitely be noticed the Super Delegates.
I would basically see Obama taking three 3 CD at best, probably 2. I could actually see Hillary winning some of hers in Central PA by greater than 60%.
A basic slight edge for Obama in WI, TX reasonably strong for Clinton, and a large victory in OH. PA could be a Clinton blowout. On April 23, 2008, I expect Clinton will have be leading in
elected delegates (possibly even elected delegates excluding FL/MI).