Poll: Which recent MLS signing will have the biggest impact?

Big names, big changes rule MLS, but who will make their mark?

The last few weeks have brought the arrival of fresh new faces into MLS, and some big challenges for the league's new heroes. Can Nery Castillo push the Fire back into the playoffs? Will Alvaro Fernandez help Seattle compete in the west, and can New England's duo help save their season?

And then, of course, there's Thierry Henry. He'll make his league debut on Saturday night in Houston, looking to lead the Red Bulls to their first MLS title.

But who will actually make the biggest impact? Vote now.