The honor cap is 4000. This is the cap on the amount of honor you can hold, but there is no cap on how much honor you can earn (just spend it so you stay below the cap).
Doing IoT and Venture Bay dailies, with the +15% guild banner and lvl 25 guild, gives nearly 900 honor/day. Toss in weekly Wintergrasp, Tol Barad weekly, JP=>honor conversion, and the occasional BG and you can deck yourself in honor gear fairly quickly.