After having spent some time on the HIDplanet forums, I would also highly suggest NOT converting to xenon bulbs w/ an HID kit. If the conversion is to be made, convert the whole headlight w/ a projector and then (only then), use a HID kit. Otherwise the light emitted from a xenon bulb in a reflector housing designed for a halogen will create lots of hot spots and ineffective light that has greater potential to blind on coming drivers.
This is one of the areas I looked at right when I got my pathfinder. The low beams are incredibly dim, but I dont think the stock bulbs are any good. In addition, the glass housing that the light has to go through is very dirty/old - if i had more time, id would thoroughly clean and attempt my1path's suggestion!