Mort said:
Arcane strike adds the to hit bonus and damage bonus to a single melee weapon - you should only apply it to one of the limbs used for natural attacks.
The feat is good as a backup - but a wizard will burn through a lot of spells very quickly with it. Also if you burn lots of high level spells for this feat - you nead to rethink your spell selection, high level spells should be better than this feat (for the most part).
Actually, doesn't it specify "you channel arcane energy into a melee weapon, your unarmed strike, or natural weapon
s?" That seems to indicate all natural weapon
s, or at least more than one. Even if it was limited, it's a free action to use, so you can choose to burn a ton of slots by infusing multiple weapons with Arcane Strike.
Useful in theurge or better yet Ultimate Magus builds. Also very nice when combined with Power Attack (which you can get for free without pre-reqs briefly with the Bite of the Weretiger/bear spells from Spell Compendium.) That +16 to Str along with a subsequent swift Wraithstrike means you can power attack most, if not all, of your BaB away and still reliably hit most things. Figure the classic 12 headed hydra polymorph (or better yet, Draconic Polymorph from Drac) + Bite of the Werebear + Wraithstrike + Arcane Strike a 5th level spell for 24d8 + 216 + 60d4 + Power Attack (figure +6 for a 12th level Wizard) = about 480 damage average. Of course that's probably monstrous overkill, even with the whole Huge reach of the Hydra. Still, not too shabby for the cost of two 5th level spells, a 2nd level spell and a feat.
(edit: forgot that for Wizards Bite of the Werebear is 7th, so that's a little more expensive spellwise, although Weretiger at 6th isn't that huge of a downgrade for 12 str instead of 16. Also forgot to factor in the cost of the Werebear/tiger spell, and possibly using Contingency to trigger the Poly/Bite combo. Still, a pretty decent way to become a pretty badass melee fighter for a little while.)