I've noticed two 16x16's in the NYT in the last couple of months. One played
a good trick on me because I thought I knew one of the theme answers,
counted it out on my fingers, got 16 letters, counted it again, got 16, gave
up on it, and then was astonished to see it appearing out of the mist as
I worked the down answers... So wrote it in, counted again, got 16 (!), and
*finally* realized this was a 16x puzzle instead of 15x. Excellent
sleight of hand... Here's that puzzle: http://www.xwordinfo.com/ShowPuzzle.aspx?date=7/14/2009&analyze=on
So... I guess even numbered puzzles are okay, at least occasionally.