Can't remember where I heard it, but Vol. 7, titled "Return to New York", will feature "The Mouse Hunters" and the 3 "Return to New York" eps (yes, another 4 episode volume!!!). Vol. 8, "Search For Splinter" will be back to 3 eps per disc
with "Lone Raph and Lone Cub" and the "Search For Splinter" 2-parter.
I've seen very small scans of the covers at
http://www.4kidshomevideo.com (click on the "Coming Soon" tab).