1...Rb1+ 2.Bxb1 Bd4# { Put aside the fact that these are bad moves: would the game be over the moment white takes the rook? What are the FIDE rules concerning this? } *
1...Qb1+ 2.Nxb1 { Normally, the game is automatically, drawn, right? } 2...Nc2# { In a grandmaster game, would the last move even be allowed to be made? } *
I believe that in this case the game would not be immediately be drawn after Bxb1 (or even after Kxb1).
From http://www.fide.com/fide/handbook.html?id=124&view=article
5.2 b. The game is drawn when a position has arisen in which neither player can checkmate the opponent’s king with any series of legal moves. The game is said to end in a ‘dead position’. This immediately ends the game, provided that the move producing the position was legal. (See Article 9.6)
However some national chess organisations override this rule with one which states something to the effect that the game is drawn if there is no forced mate.
I've often seen children play on when it's something like king and bishop each, with one side short of time. If I see it in time and I am in charge then I will declare the game drawn.
1...Rb1+ 2.Bxb1 Bd4# { Put a In a grandmaster game, would the last move even be allowed to be made? }
*[/pgn]
These position may fall under the other draw rules, since it is possible to checkmate. Positions with only one bishop or one knight are definitely insufficient force draws.