It's not going to be the questions about specific cases that gets Miers, its going to be the questions about Bush White House scandals. Bush should have never chosen someone from inside his administration. It leaves him way too vulnerable. The legality of all sorts of Bush controversies will be fair game with Miers.
I highly doubt the Democrats will even ask her much about her judicial philosophy. It's going to be all scandal-mongering all the time, and the national media will be there to see it all... and run with it. Remember the Texas National Guard controversy..? You ain't seen nothin' yet.
You know the Dems on the committee will be demanding memos, briefing papers, etc. that Miers has prepared for Bush. The WH will claim attorney-client privilege or executive privilege, and the donnybrook will begin.