I'm wondering too. Detroit 18 is probably my next amp if I can hold out long enough. If I remember correctly Bruce said last October that Detroit was on hold "until sometime next year". Which means sometime within the next 12-60 months...IF it sees the light of day. Hell, it's only been 2 years since they demo'd that line at NAMM 2013. That's nothing compared to the fabled E2...
Still dying to play a Detroit 18 though...