No. It's really not close. Rally is gaining on traditional obedience, but nothing approaches agility.
AKC agility registration numbers are literally twice the numbers of registrations or entries for obedience or Rally (the second- and third-most popular sports in AKC, since most of the others are more breed-specific and don't draw as much interest outside their breeds). In fact, it is almost exactly twice as popular as the other two sports (25K unique registered dogs were entered in at least one event in 2013, vs. 13 or 12K).
All non-AKC sports are smaller than their AKC counterparts in the U.S., so that gives you a fairly clear picture that agility is #1.
ARCHMX TDCH Pongu the Insane, CD-C, RE, RL1X6, RL2X5, RL3X2 (GSD mix, b. Apr 2010)
Crookytail the Tigerwuff, RL1, ITD (Akita mix, b. Jan 2011)