HL2 & CS2 or so the news says..

It's nothing like what they were showing on the hl engine way back when, it's been started over again about 2 or 3 times since then.

Lets take a fast-paced unrealistic game were you capture glowing flags, constantly respawn and throw yourself around a maze using grenades; and make it realistic! Surely a recipe for success!

I would have 5 years ago too. Quake had one of the best rendering, physics, entity/logic systems, and pretty good AI for its time. Building all that from scratch would have caused HL1 to be 2 or 3 years longer. Oh and HL2 isn't based off quake, but HL1, you could say its based off quake but very little is there, so really no.