You should be able to go to the store next week to check them out in person. As far as looks are concern I think they will pretty much look like the first series.
I think your best bet is to watch the videos of the folks who were at the event yesterday. I don't think Apple Store will have them for you to play with until launch day.
I noticed when Apple announced the SE they lifted the embargo on reviewers with review units talking about it before launch. Hopefully that is going to carry over with these new phones before next week. Rene probably has his review unit as we speak.