Thought I'd start this discussion!
The D7200 looks very, very similar to the D7100. These two photos come from the Nikon website:
NikonD7200.jpg 56.19KB 5 downloads
Maybe this will slot straight into D7100 housings. I know a some housing manufacturers were annoyed that the Canon 5DS fitted into 5D3 housings - meaning no sales for them and also for the manufacturers who are fast to market - no early sales boom over other brands.
Might the D7200 be the same?
As a D7100 housing owner, I am particularly interested. Especially as I only have one D7100 body and nearly bought a second earlier in the year.