A recent New York Times article explored the value of having two monitors connected to you computer. According to the report adding an extra monitor will give your output a considerable boost — 20 percent to 30 percent, according to a survey by Jon Peddie Research. 
Additionally, Microsoft Research shows that a larger screen can improve productivity nearly 44 percent. I have never used dual monitors however, data supports the idea of larger screen area so maybe getting dual 42 inch screens is not such an outlandish idea.
