Well, nobody REALLY knows for sure except the higher up's at the airlines.

I know Continental has said it will at a future date, just not right now.

ATA has also expressed interest (my guess is for their possible future Europe service).

Other than that we can all just speculate.

I'd be willing to guess there's gonna be a few US airlines that order it within the next say, 5 years (AA, UA, DL to name a few), just not right now in this economic climate.