The nomination of Samuel Alito involves much, much more than the binary abortion issue. In particular, I'm concerned about his views on executive power, which is a proxy for government power in general; I don't think someone who believes in a "unitary" or imperial presidency, as he has written he does, can truly be considered "conservative" or can honestly honor the Constitution, as Justices swear to do.
But abortion is one large issue. I'll have more to say about the entire scope of issues raised by the Alito nomination, but while his hearings are on-air on C-Span, I'll settle for linking to my prior discussion of the abortion issue
from last November. It's a long read, but hopefully an interesting and educational one.