The hype is gonna kill any possible enjoyment
Nothing is going to be good enough as we expected after all these years. And as many anons said already, unless you put some sort of long recap at the very start (which already is kinda lame, those sequences usually suck), no one will know/remember/care about what the fuck happened so far between the Humans, the Combine, the Vortigaunts, Aperture Science, the cake, etc.

I know they will never let it die because at least an ember can still warm the hearts of whoever oldfag is still around playing vidya, but in all truth i would prefer if, backed up by money, they finally dared to make some NEW games, NEW attempt at franchises, instead of yet another remake, another remaster, or in this case a sequel no one will enjoy at this point