It would be nice, but since the battery pack in the 9AN is actually ~3.6 volts and 3 surefire 123's are 9 volts the bulb won't last long. Probably make a heck of a flash bulb though, once.
I always thought it would be nice to have a setup in the 9AN like the 6R has where you can use the B65, then if you want buy a battery spacer and use 2 123 cells in the 6R. I suppose it's just as easy to turn a 6R back into a 6P but it wouldn't require taking it apart and keeping track of peices. Finding a source of sub c lithium cells like the 123's might be neat, but I shudder to think what they would cost
I wonder how a 9AN would run on one 123 cell. Probably not real well since I think they start new at 3.25 volts or so and a new nicad pack is probalby 3.7 after it's calmed down off the charger a bit. If the 123 could put out enough current it's runtime would not be bad in comparison.
If an N3 would fit into a standard 123 SF TH It would be nice to drive it with a 3.7 V 1.4 Ah Copia Lithium Ion LRB168B that would fit into a 6P body with the form factor of 2 @ CR123's.
Unfortunately, it's not form-factor compatible.
I'm curious if the 110 lumen N5 bulb for the 8NX rechargeable will fit in a a regular TH. If so, it should run for roughly 7/9 the normal run time of the 8NX assuming that the B90 is a 1.8AH sub-C pack.