2000 or so machines would be but a drop in Sony’s bucket of sales for that model.
I wonder how they avoided DMCA issues. If it’s illegal to hack the system as is, isn’t it just as verboten to reverse engineer the central chip to serve as a standalone processor?
The first PS3 versions (the ones with the first body style) come included with the ability to run Linux. It's right there in the menu to install another OS, no hacking required. Unfortunately, Sony removed that ability in the new lower-power slim version, supposedly to lower cost.
Variations of the chip itself are available to purchase though. You can get the PS3's Cell processor in an IBM blade server, and the #1 Roadrunner supercomputer is built out of Opterons and a version of the Cell with double-precision SIMD units.