I have an interest in using Pd on smaller embedded platforms, such as ARM-based ones.
Especially with the higher-end ARM chips with floating point units these days, I think Pd could have some interesting applications on the new tablets and various other ARM-based devices coming down the pipes - or already out there. Personally I work a lot with sensors, actuators, and control systems for interactive installations, and being able to run on multiple small, inexpensive processors without requiring a PC, is a big advantage that Pd has over Max, for example.
You can see with the PDa project, that it seems the gui is one of the biggest barriers to getting it to work on many different platforms.
So, if anyone's considering writing a non-tcl/tk gui, I'd like to give a nudge towards Qt rather than juce. While juce can apparently work with the iPhone, no-one has used it on any other non-intel system as far as I can tell. On the other hand, we have Qt/Embedded, which is very mature and is the standard in the area of PDAs and all kinds of mobile and embedded platforms. It doesn't even necessarily need X11, as it provides its own small-footprint windowing system.
Having said that, I understand that the first step would really need to be a cleaner interface between pd-core and pd-gui. From what I've read, there's a lot of drawing stuff going on inside pd-core that really expects to be working with tcl/tk. It doesn't seem to make sense to go ahead with a non-tcl/tk gui before this is sorted out. So, if people have programming energy to contribute, maybe that's a good starting point. Another advantage to that is to reduce the load and improve the ability to run pd-core on small "headless" processors, communicating with pd-gui over a network.
I don't know if any of this is particularly relevant or useful to anyone else, since my use-case is perhaps not so common. But I thought I'd just throw it into the ring for consideration.
Thanks!
<Jeff