the relations seem shaky at this moment; there's always the possibility it could be cancelled
the visit should only take place if there are signs that both will see eye-to-eye on certain issues that concern both; otherwise it just becomes a photo-opp.
and these photo-opps aren't cheap....Pakistanis have to close down roads, set up checkpoints and disrupt traffic....American tax payers have to spend tens of millions of dollars because the Federal Secret Service has to do costly threat assesments and bring their safety equipment on a plane to Pakistan.
a symbolic speech or two helps -- but Obama is not a man who keeps his promises. It's difficult to establish a proper working relationship with him and his admin; we had a better working relationship with the previous regime in Washington --which is quite ironic, actually.