Awhile back the RS website was showing dump-it prices on several Antennacraft models, much of it broadcast TV stuff, some of which I had not seen listed as available in years. IMHO this does not bode well for a reborn ST-2 made by another company. It would seem that if anyone was interested in the Antennacraft IP's, RS would be anxious to sell them to help defray their debts. Antennacraft seems to have been a wholly-owned RS subsidiary, or else they'd be selling their wares elsewhere. That none of these models, especially the popular ST-2, have popped up under other names seems to suggest that RS (or their new owners, Sprint) have decided to kill the brand and its products off for whatever reason.
Please bear in mind that this is all just speculation on my part, about which I'd love to be proved wrong, but one would think that if there was any value there, RS would be trying to realize it, whether via licensing or outright sale of the IP's.