I acquired this chip this week on a trip to Lake Tahoe. I didn't see it listed in the Chip Rack or James' book (in fact, unless I missed it, I didn't see a listing for any Montbleu chips in the latest edition of James' book).
I was told at the cage that these are available only to those redeeming a coupon mailed to members of the casino's players club, which is what I did, so they might not be too plentiful.