I don't know when 1.4 is coming out, but it's definitely coming out. 1.4 is going to be mainly interface improvements and bug fixes, and 1.5 is going to be major blow your socks off wowee zowie territory. We've got an office full of people working full time on DumaOS, it's just that the stuff we're working on is big.
We are planning on continuing to support all of our current products. That's the R1, the XR500 and the other Netgear routers. I imagine that the biggest updates will hit Netduma hardware first because Netgear are in charge of their own firmware release schedule.