While someone inevitably will try, I don't see it being good. The hallmark of the Half-Life series was not its plot, but an almost compulsive obsession with the gameplay quality. Few professional studios could rival Valve in that, let alone a fan project.

I mean, I don't know if you've seen Black Mesa (the game), but they've done an incredible job at making an HL1 reboot, with some levels drastically expanded, a lot of things tweaked, and it's amazing how well it works.

Valve doesn't have a monopoly in gameplay quality - they're just very consistent about it.

Black Mesa is great, but it also took over 8 years of development for first release and it still isn't done (last I checked the Xen chapters aren't in). So that's 13 years of development and counting.

They also had the entirety of HL1 to build the game from. Obviously they created a ton of unique assets and reworked stuff, but they had an entire game to work from.

Trying to make a full 'mod' of Episode 3 is nothing like Black Mesa and would be an incredible amount of work. With that said, I would love to see someone try.

I found Black Mesa to be crappy, to be honest. I don't know how anyone could imply that they were on Valve's level there, except in terms of leveraging much newer engine technology. I played the first public version and maybe it has improved...