I'd say keep BD and have a cheaper non BC version instead. Without BD, games would all be HD DVD now, and MS was a big part of the organization on that side of the format war. I couldn't ever see SNY allowing that to happen. Would that push SNY to go all digital sooner like MS is trying? Something more user friendly than cell probably would've helped, but I think SNY could've gotten away with it more so than they did.
A $399 base PS3, without BC at launch, would've had 360 around 20-25 mil behind where it was, by 6 years in, with PS3 scooping up those sales. While cell may have been a pain, as long as PS3 sales were strong enough in comparison early on, it would've pushed devs to put a lot more effort in much sooner. 360 being in the position it was, gave devs breathing room they wouldn't have had otherwise.
Quite a few people I knew who had PS2's, had 360's earlier on. It was the console to get, and many others jumped in because of that. Some of them ended up grabbing a PS3 once it went slim and became cheaper, whether they added it to the 360 or transitioned fully to it. Getting a solid start to sales at the beginning of the gen is fairly important to long term sales, in general.
