I wouldn't consider that the 9530 a successor. I would look at the Javelin/Niagra phones to be the successor to the 8800 only because the phone would operate very similar. The 9530 w/ the touchscreen would be a total change. I see successors as something very similar with minor upgrades.
the 9530 would be the successor if it was available on all carriers eventually. but it will only be available on verizon (US side that is.) i think the bold is suppose to have a short stint as a AT&T only phone (i may have heard wrong on this). the javelin could be the only all carrier phone that is similar to the 8830WE. but i can't wait for the thunder to drop on verizon as i will be one of the first people to call my business rep and get my hands on one.
The two phones that you have listed below are NOT successors to the BB8830WE. By definition, a world edition phone is capable of both CDMA and GSM in the same phone. Neither of the phones that you listed have this capability.
Again, I will ask the question: "What BB phone will be a successor to the 8830?"