Heath Schuler, for one, is a pro-lifer. I seem to remember two other's were as well.
The interesting thing about this is they have 49 plus 2 caucausers. The R's are in no mood for disloyalty, and we only need a couple more. McCain is running for President - no way he goes off the reservation, or its retirement time for the old hob.
Specter may try to drift, and the two nutjobs you site are certainly possibilities.
Casey's father was pro-life, but the empty suit son refuses to say how he'd vote. Let's just say he's heavily beholden to liberals and can be counted on to vote whichever way they indicate.