Sony's main motivation in providing OtherOS functionality was, as always, money. By being able to run alternative OSes PS3 was classified as a computer and not a console for tax purposes, and Sony had to pay less tax because of that. I'm not sure what the actual numbers are tho, so someone else feel free to chime in.

One funny side effect of this was that dev kits for the PS3 were rack mounted 1U (?) units. As a game developer this was ridiculous because we each had one of these on our desks, usually with a tv sitting directly on top of it. Thankfully this was changed to something reasonable on PS4. The PS4 dev kits are pretty cool looking IMO.

I remember articles about the massive racks of PS3s in Linux clusters for people who wanted to use Cell for large parallel computing.

Did Sony/IBM every actually release viable/affordable Cell hardware outside of the PS3, or is Cell pretty much dead now?