Sounds like you guys need to bring your A game to this one. Mommy and Daddy sometimes perpetuate problems because we let it happen in the first place. Set the expectation, teach the expectation, and don't deviate from the expectation. Be tough mom and dad. If you don't want to be rubbin' his head when he's 12, don't do it now!
Put him in the bed. Read ONE story. Talk about your day today (best part, what did you learn, etc), talk about what you're doing tomorrow. Give a big kiss. Assure him that you can hear him in the monitor (show it to him if he's never seen it before), and turn on the nightlight and LEAVE THE ROOM and close the door.
If he says he's scared....teach him to scare away scary thoughts by thinking of something fun (like playing with daddy or going to the park). Also, teach him to hold his bear/lion/lovey and tell him that his lovey wants to hear all about his day what what he plans to do tomorrow. Tell him that his lovey is tired and he should help Lovey fall asleep fast.
If he gets out of bed....go back in, put in back in bed and LEAVE!
If he screams....assure him that you can hear him just fine without the screaming. "Just use your words, not your screams, and mommy and daddy can hear you, but we're tired and the family is going to bed now. Goodnight!" :)LEAVE THE ROOM! If you're not going to bed right away (our bedtime is at 8:00 - what grownup goes to bed at 8?!) tell him that you've got work to do and you'll check in him again when you're done. Usually, they'll be asleep before dishes are even finished!
Best of luck!