Joining in!
With PhotoPass+, you can still have as many regular PP cards as you'd like. When you get home, you load them all into your PP account. You will need the PhotoPass+ card to add any attraction photos though and you'll only get one of those. You will also get the photo package at any participating restaurants...you will get the photo package delivered to your table and you'll also be given a receipt with a PP number on it (looks like the code on the back of the cards). You can then add that photo to your online account.
As far as the princesses go....Tiana should still be meeting over in the gazebo by Liberty Square and Ariel is in her grotto next to her ride. Merida is in the Fairytale Garden (located off the walkway from the Hub to the tea cups) and Rapunzel is a tricky one. During
MNSSHP, the princesses do typically meet with their princes (as a previous poster mentioned). There will be a few of them at the Town Square Theater and you can ask a CM who will be in there.
Now, we still need to wait and see when Princess Fairytale Hall will be opening. I think that they are aiming for Fall 2013, but that could be anytime from late Sept-early Dec.