I need to change the carrier bearing along with the u-joints on the driveshaft for a 2003 Dodge Ram 2500 4 wheel drive. Question I have is the two driveshafts at the carrier bearing pressed on or will they just slip apart?

 

you have 2 carrier bearings in a differential, one on either side of it, and yes they are pressed on. the bearing that is aligned with the drive shaft is the pinion bearing, and yes it is pressed in as well,

 

not in a differential ... he is talking about the center support bearing for a 2 piece driveshaft.
but yes they are pressed on. you will need a press or a special tool to dissassemble.
make sure you mark the 2 peices for easier install. (tire chalk or something similar)

edit. the driveshafts will slip apart after you remove the slip joint boot but the center support bearing is actually pressed on.