It's an interesting idea...now, granted, the services apparently didn't turn out for Pan Am, but for a more serious airline like jetBlue, they just might. After all, the passenger volume would sure be higher than Pan Am, so you could justify having a few car rental companies/"express" fast food stands, etc.
Also (and you can correct me if I'm wrong about this), my perception is that the government officials controlling BLV are desperate to get a carrier in there and promote the airport's growth, so that the project doesn't end up being a complete white elephant. This might benefit jetBlue greatly, in that they'd possibly get reduced landing fees, free gate space, etc. in order to be the "seed" airline, so to speak. Perhaps that way BLV could craft itself a niche in being the airport that all of the discount airlines and charters serve in the STL area.
I do agree that BLV does not seem like jetBlue's typical airport--but, then, jetBlue is not a typical airline. I could see it happening, especially since competition in the area has taken a major hit with TWA getting eaten up by AA. Perhaps a JFK-BLV-LGB route would work well. Or a IAD-BLV-FLL route. The possibilities are rather interesting. I'm going to keep this one on my radar.