Last October (2014), when I was researching whether my black and white prints could be improved over Epson's OEM product, the two solutions that presented themselves were ImagePrint and Piezography. I ended up going to Jon Cone's K7 Piezography system, but certainly saw great potential in ImagePrint's RIP. What's interesting is that even then, eleven months ago, ImagePrint 10 was supposedly "imminent." I'd have to agree with the OP that such a long period of "any day now" does not bode well.
I'd also agree with Mark that the new Surecolor inkset in the P800 is a clear improvement over its predecessor and the output from OEM ABW is truly outstanding - though not quite to the level of K7 Piezography. That said, the license cost of ImagePrint is not trivial. I can certainly understand the desire to make use of an expensive product one has already paid for. And I, for one, would love to hear how that RIP works with the new inks.
One, indeed, hopes ColorByte gets their act together.