That's silly.
We have seen what one generation of developers did with Half Life.
Let's see what a new generation can do. The IP to me is like SW, or Batman. Let different guys have a go.
I agree with the first sentiment, which is still ultimately what you would get with Valve, which is far different today than what it was, with many of the old guard having retired. What make me more interest in a Valve HL is the mentality the company still has toward development in general. The fact that an "easy" solution of just making more HL for the sake of it hasn't happen is already good to me. HL2:EP2 while awesome, was also getting pretty dry. I really don't care about a Naughty Dog / Nintendo / Insert-fan-wet-dream-here version of HL, because ultimately all those companies are better served making their own unique IP and direction, filled with their own character, mentality towards any game world.