1. if there were serious side affects such as cancer, stem cells turning into cell types other than neurons, this might pause other brain stem cell research.

i'm not going to worry about the new implanted cells eventually becoming "diseased".
researchers are also working on neuroprotection.

new cells might be the only "cure" for advanced pd'ers and researchers are playing catchup after BUSH set stem cell research back a decade.

remember dennis turner's autologous stem cell implant back in 2000? one patient was the total trial!!! so it could have been a sham but if the affect was real, turner got a few good years.
http://www.stemcellresearch.org/testimony/turner.htm