No experience points for wand kill
Zapping monsters to death provides no experience in 1.2.0p3.
Level 8 high elven ranger made it to the high mountain village. There was a stone giant outside. I zapped an unID wand, which turned out to be cold. I thought I would gain a level for downing such a mighty foe, but I checked the monster memory and it said, "So far you have killed but one stone giant." That was it. May be related to certain potion kills also granting zero experience.