Heroes is starting to woo back its lost viewers. If it finishes strong (with a tacked-on season ending) then it could gain from a long hiatus. We could forget how boring this season was, and be ready for the show to reinvent itself.
Doctor Who is set to air new episodes in England this spring, plus a Christmas episode next month. If the Sci Fi Channel is smart, it'll negotiate to air those new episodes as soon as possible, during the American TV drought. Also, a whole season of spin-off show Sarah Jane Adventures has aired in the U.K. but not the U.S. yet.