SBC might not be finished.

(context: While SBC and BellSouth Corp. are focused on helping combine AT&T Wireless with Cingular, which SBC and BellSouth co-own, SBC might not be finished. )
What does "SBC might not be finished" mean, esp. the word "finished"? And what does "while" mean here? I don't know the logical relationship between the first part of the sentence and the last part of the sentence.

[RonBee]

SBC might not be finished doing what they plan to do in that area.

~R