I doubt it. Gandalf didn't do to much in ROTK while in a battle situation in terms of magical power. Luke runs up to Gandalf and slices him in the face with his lightsaber.
Although I'm not a fan of The Lord of the Rings...so I don't know much about Gandalf's abilities.
But DN Luke is a virtual demi-god too...so...
I have no idea seeing as I don't know anything about Gandalf's powers. He didn't look like he did much in the movie though. Luke would cut through a good deal of that army that attacked...Gondor (sp?) by himself I think. But again, I have no idea.
But the thing with LOTR characters is that they look to be sucky and in all terms are sucky but they simply rock anyways.
For one reason or another they just do. You can't beat them, you may be far more skilled have done more stuff have more training and a greater control, but Gandalf will just do something he has never done before and becomes leagues above you and destroy you, even though he logically shouldn't be able too.
Lotr characters pwn because they have strange magicall things that nobody really understands.