The proliferation of ARM platforms is definitely a huge problem from a distribution development standpoint. As of now, we have eight different kernels we package for eight distinct ARM architectures, across two different repos. I don't spend much time on the older plug platforms anymore except for keeping packages built and up to date. Their lack of horsepower and connectivity options limits how much you can really do with them, so worrying about getting XBMC built is a complete waste of time. Nearly all of my development time is spent on armv7h to support Cortex-A boards, of which I own a Beagleboard-XM, Pandaboard, and Trimslice. At the beginning of next year I'm looking at adding the Origen board with the Samsung EXYNOS Cortex-A9 chipset and MALI GPU.
I also only focus on dev boards since they are by far the easiest to work with, and in the case of beagle/panda impossible to brick. We have some work going on for the HP Touchpad, but I haven't dived into that yet. The best case to be made for consumer/retail devices is that you're getting some top-notch kit at a serious discount. Find almost any dev board that is the same system as a tablet, for example, and you're looking at some outrageous price inflation. That's also why I never invested in those touchscreen add-on kits for these boards, I simply can't justify that expense. But if you can break into a retail touchscreen device that costs only a fraction of the dev board equivalent, you're in business and on the cheap.
Though while I do spend most of my time on v7 boards, like I said the majority of that is just getting software built and packaged. In a way I've slowly been migrating to a stance as a facilitator for others to expand the board capabilities with the software we provide, as opposed to a device developer/debugger that figures out the tough questions to get every feature on the boards working optimally. I work on the core device features to get interfaces exposed or functionality enabled, but when it comes to the "extra stuff" like audio and video I just haven't had the time. Beagle and Panda are themselves particular issues in the video segment, since PowerVR and/or TI has not made any move toward providing hard-float binary drivers for the SGX GPU that is on the boards. But the hard-float transition is sweeping the entire ARM distro world, with Debian, Fedora, and MeeGo (RIP) maintaining hard-float ports, and with Ubuntu slowly getting on board. Eventually I predict that the upstream manufacturers or NDA-strapped devs will be pressured to start releasing hard-float drivers alongside the standard softfp variants.