I remember you could do SETI@home and protein folding with PS3, the power was decent at the time, but the lack of legitimate fans and good cooling made the machine absurdly hot. Overall not a good idea to mine with a console, specially in the summer you can kiss it goodbye.
I'm not really an expert on the calculations done by SETI@home, but I believe that it uses quite some sophisticated set of instructions that have to be performed. Bitcoin mining (like every SHA256 coin) is rather stupid when it comes to the operations that have to be performed (that's why it is relatively easy to construct ASICs for that and why they're so effective). If you can only use a multi purpose CPU for the calculations (like SETI@home), though, everyone's stuck with those processors and no one has an ASIC-advantage!
