Dammit, I was gonna say absolutely not...
Anyway, given most of the community's choice, assault rifles would fire rockets. Scratch that, every weapon would fire rockets and be fully automatic. No. If 343 cave in to people's demands, they will be shown to be weak and people will know that with enough pushing, they can do it with 6,7,8 and 9. Much like (X) company with the Mass Effect 3 ending, or Bethesda with Fallout 3's. if they dont listen, it shows them to be able to do what they want.
Though forge palette/maps and reintroduction of race, that is broader type stuff that is sensible but some weapon/story/vehicle/ general gameplay ideas ive seen are... Just awful... When people think of weapons, they don't think a drawback. Ergo, the ultimate weapon that can't be defeated...