The Essentials classes absolutely generate fewer conditions than pre-Essentials characters. In fact, one of my the things that is making me consider going Essentials-only for characters is that it seems to eliminate the "everybody is a controller" syndrome that so plagues higher level pre-Essentials parties.
In Essentials, I think you'll find that wizards and warlocks generate about the same number of conditions as they always have, but all other classes generate far fewer. With mid and high level pre-Essentials parties, you'll often see the entire party (including defenders and leaders) open up fights with multiple stun, daze, slow, immobilize and restrain effects. An Essentials only party should have less of those shenanigans.
In Essentials, I think you'll find that wizards and warlocks generate about the same number of conditions as they always have, but all other classes generate far fewer. With mid and high level pre-Essentials parties, you'll often see the entire party (including defenders and leaders) open up fights with multiple stun, daze, slow, immobilize and restrain effects. An Essentials only party should have less of those shenanigans.