<crickets>

Okay, I'll bite. Yeah, as long as your chainline is good, and the chainring that you leave on is still soundly connected to the crank, it will work fine for a single-speed. Some people might say that it looks ugly or something (and it may) but it will still work.

Other people would say to not even bother taking off the other ring. That way you can use the larger ring if you want to change ratios. Some folks call this a "hobo single-speed" but it works, and Rivendell uses a 2-ring setup on their quickbeam. You don't see many hobos riding those.