I think I remember reading somewhere the next issue would be mailed in "late" February. Back issue collections are available on CD-ROM, so buy a set of back issues to hold you over until the next "new" issue arrives.
My favorite articles in the "Reader" are the ones that relate to the "classic" bikes of the 1950's to 1980's era. Unlike articles in "Bycycling" about the 2007 Shimano shifters, Rivendell articles never go out of date.