But I still can't believe there aren't' a million people editing 1080p on these rigs here yet. Maybe it's just that no one is using FCP X.
I can edit 1080 on a first gen MBP without skipping frames if the footage isn't grouped on Avid Media Composer. The issue might just be FCP. Try a trial version of Avid MC. And no, professionals are not using fcpX. They gimped it for professional use and have slowly released updates to get semi-professional features back. I edit on prime time network tv shows and we use nothing but Avid MC.