I don't see this mod dying anytime soon... sorry.
As far as this what mod will become? I don't have slightest clue, the "transformation" (no pun intended) from alpha to beta was more than anyone expected. So, who knows what this mod will become once it hits the "versions."
You also have to think about Half-Life 2 coming out soon, and how it will manipulate how many people that will stay around, living the soon-to-become-nostalgic life that is the 1998 game of the year.
But, this thread shouldn't be about ESF going to Half-Life 2, because the team has stated constantly, and made it a stern point... that ESF will remain on the original Half-Life.
Overall, I say let's just sit back, be patient, and let PcJoe, harSens, Darktooth, and the rest of the crew surprise us(since they usually do). They'll have my support. :]