All the Twins starters now have one appearance under their belts. Obviously we don't learn a lot from one two inning outing. But there are some things that have changed.
Pelfrey got hit hard in his start and his velocity was down. That my not be meaningful, but given that he is coming back early from Tommy John surgery, its also not reassuring.
Harden is not on a regular pitching schedule. Neither is Perez. It seems unlikely they will be ready for opening day and almost certainly not as starters.
Gibson had a good outing and looked like he may be ready to start the year in the rotation. Again, there are a lot more games to go. Hendricks also had a decent outing.
Diamond is not pitching yet and probably won't be ready opening day. The Twins won't need a fifth starter for the first time until a week later, so its possible he will still fit into the rotation.
Worley and Correa did fine in their first starts.
DeVries and Deduno only got one inning in their first outings. That may indicate they are not serious rotation candidates.
Walters had a good outing in an intrasquad game, he has yet to pitch in a regular spring training game. Same with Hermsen, Myer and May.
Here is a revised pecking order: