Halos Future, what could it be?!?

What could the future hold for halo?  We know Halo 3 is coming out next year (so they say), but what after that?  Could they go into the past? Or the future?  Both could easily happen, and I am sure both have been discussed at length in all the fan site forums.  But what I want to know is how will Halo be remembered?  In this day and age of merged mediums (web, TV, movies, books, games) could Halo be the next huge franchise? In twenty years will it be remembered? As what? Ground breaking entertainment, the first truly huge video game franchise.  Is Halo currently raising and setting the bar for all that are yet to come?  Could Halo be this generations Star Trek?  In 30 years will we still be getting spin off shows, games and movies, could it get that big!  The sky’s the limit my friends, Star Trek started as a few episodes and keeps going and going and going.  Thinking about all the possibilities gets me just way to excited!