President Barack Obama (D) is scheduled to address a joint session of Congress tonight 9pm EST. This is not an official Presidential State of the Union address, as new Presidents traditionally give their first State of the Union address after having served nearly a year in office. Traditionally, this initial address is referred to as an ‘annual message’ or other similar, generic title. Obama’s address will be followed by a Republican response to be given by Governor Bobby Jindal (R-LA).
As always, I recommend watching C-SPAN for unfettered, uninterrupted coverage of both.
The Constitution requires that the president report to Congress annually on the state of the union, but does not specify the method or form of this report. The in-person State of the Union address has been a tradition since 1913 (transcripts 1945-2008 available from C-SPAN).