In addition to buzznina's info, this from the CBR resort thread:
It has been reported that during busiertimes, two buses will enter the resort at one time. One bus will service one side of the resort and the other bus will service the other side of the resort. For example: Two Magic Kingdom buses enter the resort at the same time. One will pick up in Jamaica, Aruba and Barbados and then leave the resort. One will pick up in Martinique, Old Port Royale, Trinidad North & Trinidad South.
Basically- just go to the nearest bus stop in the mornings. Chances are if you aren't on the bus waiting to finish making the internal stops, you're waiting at the bus stop for it to get to you. Either way, you're waiting.