Occaisionally (usually after coming off of a highway exit ramp), my transmission will make a noticable "thunk" noise either when I come to a full stop or right when I begin accelerating after stopping. Based upon my dealer's reaction, either they're not concerned, or they haven't experienced similar complaints. Has anyone experienced this problem as well?

Something new or has it been happening ever since you bought the vehicle?

Go through the owner's manual, it might be normal. I know with my 98 4runner, it mentions that in the manual as normal, so it might be a something 4runner's are known to do.

Something new or has it been happening ever since you bought the vehicle?

Yes - it's been happening since I bought it. I'll re-check the manual and see if there's any mention of it in there.

Consider going to a dealer and "test driving" another vehicle identical to yours. See if you can reproduce this behavior. If you can't, you have some evidence that your truck is not behaving normally.

This noise sounds alot like the noise you would get from a dry spline in the driveshaft. You might consider greasing the ujoints and drive shaft splines with moly grease. I know it is a new vehicle, but it wouldn't be the first time some grease was forgotten at the factory.

or have it looked at under warranty.