Eh. It's not going to be particularly exciting. Since the Munich is the highest kilned of the four, it is going to contribute the most to the flavor. You will basically end up with a base that's much more malty than 2-row, but much less malty than Munich, so like a watered-down Munich flavor.
This is kinda like mixing together four different brands of cola. The end result is just....cola.
Base malts aren't very exciting in their contributions to the beer beyond their efficiently converted starches. You need to experiment more with specialty malts if you want interesting contributions to your final brew.
Primary #1 - Midnight Ryeder (Midnight Wheat and Rye)
Primary #2 - Florida Weiss
Primary #3 - Kane-DOH APA (Honey Citra APA)
Secondary #1 - Downtown Flanders Brown (brewed August 2012)
Keg #1 - Raspberry Florida Weiss
Keg #2 - Cinnamon Raisin Cider
Keg #3 - NONE!
Bottled - NONE!