not sure if this has been posted yet, but I was looking at the rebate form and the Hero is listed on the same column as the Pro 2, Pro, Diamond etc. that requires only activation on data plan $25 or higher
http://www.nextel.com/assets/pdfs/en...mir_103109.pdf
The Pre, and 3 Samsung Instinct phones are listed separate on the left with a note (requires activation on select plans)
this would lead me to believe that the Hero indeed will be available on existing SERO plans
just my 2cents
edit
saw this too so now i'm confused again....time will tell i guess:
http://www.nextel.com/assets/pdfs/en...mir_103109.pdf