Arcane channeling
The way I read it, the touch spell applies to every attack in the full attack. So at 13th level (when you get arcane channeling:full attack), your full attack is 3 attacks (base +13/+8/+3). Each attack that hits does normal weapon damage + touch spell damage.
The most devastating use I can see for it is with vampiric touch. If all 3 attacks hit, your opponent takes 18d6 (6d6 x 3) damage with no save, and you get the same number of temporary hit points. If the bad guy is still alive, do it again next round (at 13th level you have 6 + Int bonus 3rd level spells).
It seems to me there should be some limit on the number of times per day a duskblade should be able to use arcane channeling, tied either to level or Int bonus. With the huge number of spells per day a duskblade can cast, I can see the ability getting out of hand. I love the class, and I really like this ability, but I am concerned about arcane channeling and game balance.
Rob