no because
1.it would look weird
2.spartans can't get infected by the flood
3.playing as an infection form would be weird and infecting some one ewwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww wwwwwwwwwwwwwwww
Edit: for every infection game it would be like that but if you could turn it on/off it could work (virtual no one would use it probably though)
[Edited on 07.03.2009 2:45 PM PDT]