I'd love to find a 1xAA lux torch, but as the above posters suggest, I don't think there is one.
The closest I know of is the Tekna Splashlite LS which is a tiny little polymer CR123 luxeon torch. Pros: fenix P1 sized, tough, long battery life, simple twisty. Cons: crap beam, not too bright, plastic lens easily scratched. Overall a great emergency torch but not good enough for general use if you've owned any of the remotely decent lux torches which have come out in the last 12 months!
I think the problem with small plastic lux torches is heat dissipation. The ProPoly gets away with it by having a big metal reflector which heats up and dissipates some heat out through the lens.
I think there's be a market for a cheap underdriven lux 1xAA plastic torch: small, light, long battery life, few overheating problems etc etc