So far Nintendo Japan and Nintendo UK (sure to follow NOA) have announced a new Nintendo Direct for tomorrow at 2 GMT (9 AM EST). The direct is said to focus on upcoming Wii U games and features.
UPDATE: As I mentioned above, NOA just announced confirmation that it will hold a Nintendo Direct at the same time (6AM PST / 9AM EST):
Visit http://www.nintendo.com/nintendo-direct at 6 a.m. PT/9 a.m. ET on Wednesday, Jan. 23, for a Nintendo Direct focused on Wii U.