Back on an earlier topic - I don't buy the idea that numbers are going to increase substantially on the 13ers as a result of spillover from the 14ers. As Darin mentioned, there are ten times as many 13ers to choose from, and to take it further, many of them are more difficult than the hardest 14er, require more routefinding, don't have CFI constructed highways to the top, are looser and potentially more dangerous, and have much less info out there to go off of. There are many facets that "grease the tracks" for people to hike 14ers, the absence of which would likely prevent a portion of people from attempting them. I also don't see the obsession with The List going away anytime soon, which if we're being completely honest is the primary motivation for many to get up there and hike. I know a few people who have finished the 14ers and quit hiking peaks altogether afterwards, which I'm guessing is fairly common. With the 13ers, save for the Centennials, the list motivation is not realistic as there are 500+ ranked 13ers. Let's also not forget that a lot of 14er summer traffic, particularly on the easier peaks, is comprised of people from out of town who come to Colorado for a week or two a year and want to get some high peaks in. It's not likely that kind of traffic would spill over onto the 13ers, for obvious reasons.
I'm not trying to be an ass or sound like an elitist or something, I'm just bringing up some observations and facts that make me think traffic will not increase substantially on the 13ers as the 14ers become more popular. There may be a few close to Denver that turn into the 13er version of Quandary or Bierstadt, but I doubt we'll ever see a conga line up West Partner Peak in the Gores.