i also just pulled all the plugs to see if they were fouled up since new plugs helped so much before. All of the plugs looks fine. They have a little crud on them, but it doesn't look like they are so fouled up that they aren't sparking.
I did want to ask also if a rusty connector on an ignition coil is a problem. I haven't been able to find much info on this, but i noticed when I changed my plugs and wires that one connector on the 5 2 coil pack is rusty. I guess I should check for spark, but I don't know if it would make a difference at idle since it only seems to have problems when the engine speed drops as I slow down or when the car shifts gears.
I suppose it could also be some sort of air flow problem. I replaced my air filter when I did the plugs and wires. Would it be best to check the 02 sensor, the MAF sensor, or the MAP sensor first?