We already knew a new Frozen meet and greet would be coming to the Norway pavilion. The sisters would be moving in once the new Frozen ride was in place where Maelstrom formerly stood. But I don't think many anticipated the scale of it.
Stitch Kingdom uncovered a filing to begin work on the new structure called simply: "Frozen Meet and Greet Building." The new structure will most likely be themed around Frozen and Arendelle which will be more of a departure from Norwegian culture. The facility will reportedly be 13,000 square feet, much larger than your average meet and greet.
Rumors floating around attribute the large size of the building to possible show elements to the meet and greet. You could look to the Enchanted Tales with Belle meet and greet and the Thor meet in Disneyland which both have elaborate pre-show elements. The new Anna & Elsa meet could have something similar.
I think we could expect Olaf to make an appearance in the new venue. I doubt there will be enough demand for a Kristoff meet to warrant a dedicated space however. I also think the large space could anticipating for the huge queue size the sisters previous meet and greets attracted. We could also see Disney try something new here and incorporate the pager system seen in Dumbo. There could be elements of the Frozen Summer Fun play areas inside the building to distract younger visitors and give adults a chance to sit before meeting the characters.
The new Frozen ride inside the Norway pavilion is scheduled to open in 2016. This new facility will have a lot of catching up to do.