Fizzled out or not, the Phis are very interesting. The 10x Phis for 1k that Colfax does was too good a deal to pass on when I heard about it mid last year. One interesting way I have found to house and power them is to get an old Tesla S1070, remove the ancient Teslas and put in the Phis. The S1070 is more or less just a plain old external PCI-e expander chassis with a huge power supply.
Due to some limitations which I have not bothered to track down yet, one Tesla needs to remain plugged in or the s1070 won't stay online. Still though, 3 Phis in 1U is pretty decent. The S1070 systems are pretty cheap these days too.
The S1070s fans can be a bit intense (I have never heard fans soooo loud) but that can be fixed by intercepting and replacing the PWM signal used to control them. Attached are a few pics of what it looks like.