Not sure why he hasn't opted for this. He seems obsessed with getting his hands on it (even so far as to try the N64 version)... but hell... take your pick of an emulator and its got a Doom port:

http://en.wikipedia.org/wiki/Versions_and_ports_of_Doom

Chances are even DOSBOX could run it with some work.

On topic, however, some of our hope may lie in Pandora devs getting a nice, clean version up and running that can be ported to Maemo.