After sitting in on the preliminary planning for season four, Bryan Fuller has again left "Heroes." From AICN:"Development was really starting to heat up, And it appears like I may be writing multiple pilots for NBC so that wasn't leaving a ton of room for 'Heroes,' unfortunately," the star writer-producer tells AICN exclusively. "We crafted some really great arcs for the season that I'm excited to see come to fruition. I love that cast dearly and am sad to go, but the plate -- she was over-flowing."He'll be missed, since things started to spark again once he came back at the end of last season. It'll be interesting to see what he comes up with for pilots.