The seeds of the future are placed in the present. I try to build a campaign in such a way that the players have at least some idea of what is comming, or that the PCs know an area before the adventure happens. Last year I began running 3 campaigns at roughly the same time, all taking place concurrently in different areas of my campaign world. One of the groups began in the town from the Iron Satyr Dungeon Adventure. That adventure is for fairly high level characters, and I still have yet to run the adventure for those players, but at some point I will.
If the players and you dont have an idea for what comes next, or how to segue to the next adventure, then perhaps it's time to schedule some down time for the characters. Let them go to town, spend their money, do some social activites, use those item creation feats they took. Pretty soon, they'll be lookin' for an adventure and you won't have to lead them anywhere.