Shimano's Home page http://bike.shimano.com/ has a survey, asking about tire sizes, including 650B! Tell 'em what you think!
Below is what the survey results were as of this morning:
Question of the month: : What tire size will your next mountain bike have?
Mtbr's 2016 Winter Biking GearReviews and Roundups
Results 1 to 9 of 9
Thread: Shimano interested in 650B?