I can't really say if there's going to be some sort of an installation in MGS4. I guess there might just be one, considering how commong they are becoming. Luckily I'm pretty sure Kojima doesn't want the install to be too long. But then again, he might just think the game is more important (which it truly is).
I don't really like installs on consoles. So slow compared to PC. However, I guess I'd better get used to it. Still I cannot accept mandatory install on bad (well, not so good) games such Lost Planet and DMC4 probably are. I think even Oblivion had some kind of an install (5.5 GB) but it did it in the backgrounnd. I can't really understand why other games can't do that.
I think I'll be able to survive through the installation of MGS4 although it is probably my most awaited game since MGS2.