To those who are saying that it's up to your 4e DM to make forced movement useful: That's like saying that it's up to a 3.5 DM to make monks useful. If an ability requires your DM to pay special attention for it to be valuable, it's a bad sign.

Many of the other things people are saying also don't make much sense. Push the enemy next to the Fighter? A fighter can only 'sticky' one enemy at a time, and if he's close enough to have an enemy pushed into him, he's close enough to just walk up to the guy on his own turn.

The fact is, most fights don't take place surrounded by deadly terrain hazards. If your DM sets it specially up so that they do, that's nice of him, but it's not something you can really count on - and even then, the smart enemies won't stand next to the nasty terrain anyway. In all the 4e games I've seen, I think I could count on the fingers of one hand the number of times forced movement has really made a difference.

That said, forced movement can be useful - but it's only really useful if you build specifically for it. It's shouldn't be a surprise that the one situation in which forced movement really is good is when the party can guarantee that there'll be deadly terrain hazards by making their own. Shoving an enemy back and forth through a damaging zone is probably the best way to use forced movement, and it can get downright abusive if you combine it with Teleport. ("I teleport the bad guy five squares north and five squares up, so he drops through four vertical squares of my Wall of Fire and takes damage four times. Oh, plus the fall. Is he dead yet?")

- Saph