Microsoft blames PS3 delay on "unproven technology"

Xbox UK boss Neil Thompson has told GamesIndustry.biz that Microsoft is not surprised Sony has "backed away" from its commitment to a global launch for PlayStation 3.
"We know how challenging it is to pull off a global launch, so it's not surprising that Sony has backed away from their previously announced launch plan, due to the unproven technology they are trying to pack in to their console," he said.

GamesIndustry.biz