There is a subtle difference between a waffler and a fence-sitter, most notably in that the fence-sitter never actually decides their stance on an issue/issues.
This term is derived from the food of the same name (waffle), probably because the grid-like patterns on the food resembles how a waffler is on again and off again on their views.
The word has recently made a return to the forefront of common communication with the arrival of John Kerry's (United States) Presidential campaign.
Can anyone seriously say that with a straight face? What a waffler. This guy panders so much he makes Al Gore look like a decent person. I feel sorry for anyone who lets themselves get hoodwinked into voting for this fool.
Ben (Employee) "Ohh that looks like the good old fashioned waffler. I bet that was Maurice, he gave Marshal one last week."
Dave "THAT SON OF A BITCH IS GOING TO GET IT!!"
This is considered an entry level position and the employee will usually work hard in order to acquire a promotion to fluffer.