My current light set-up ain't gonna cut it. I had reservations that it would, but tried it anyway. Last time I asked, I was only interested in cordless/wireless/self-contained units... That's still a preference, but no longer a deal breaker.
-Bright enough to play with traffic. My little 3xAAA light is fine around the block, but not on the commute.
-Able to handle the weather, so basically waterproof.
-Work out of the box, with no DIY'ing on my part.
-Durable (see above)
-Dependable (see above)
-Secure mounting. I don't want it to budge until I take it off.
-Runtime at least 2 hours on high for something with an external pack. Flashlights would consider 1.5 hours on a single cell (if possible)
Prefer US-sourced. I realize that damn near everything is imported, but from reading, domestic suppliers have better, more responsive customer service/warranty.