I ordered a dingoo last week.
It's an interesting little console from a programming stand point: basically it's just a all-in-one processor based on MIPS32 architecture with an integrated AC97 codec and some other parts to control the sd cards, usb, lcd, etc,. Apparently there's also a 4gb NAND inside the console which is good.
But the part that really makes it interesting to me is the SIMD instructions set extension added to the processor (there's no FPU on board apparently), i think it's more or less equivalent to Intel's SSE extension and i don't think that they've been used in homebrew emulators yet (?), it surely improves graphic rendering and could also be used for 3D too (i even wonder if it would be possible to emulate a PS1 with all this),
All in all, it's much easier to program that multi-chips/multi-processors consoles, the OS is open source and rather small (they use uCOS-II), + there's a TV out, all win.