The situation from the diagram you posted is a draw by both FIDE and USCF rules, as the only possible continuation from this position is Kxc7#. Thus, Black has no mating material.
I know that, but is chess.com smart enough to know that?
Chess.com have identified a number of situations (K+P vs. K+N, etc.) that are considered to be drawn. They're not always correct, but computer programming has its limitations.
Here's the history of the current rule. Read Post 96.
http://www.chess.com/forum/view/help-support/no-mating-material--draw?page=1
White has to play Qxg4+ to secure the draw. Any other move such as Qd5+ would probably lose for White as after Qd5+ Black moves his king and then White runs out of time and then Black wins because Black has sufficient material to mate [the pawn could become a queen] and White loses as White has run out of time.
duh lol
The situation from the diagram you posted is a draw by both FIDE and USCF rules, as the only possible continuation from this position is Kxc7#. Thus, Black has no mating material.
The game should never be adjudicated based on material alone and abstracting from the final position - if the side who still has time gets forcibly checkmated or a stalemate of any side is forced, it's a draw.