I don't like it one bit, but boostpacks are a fact in NHL 10.

Here you can find a complete list och different boosts for xbox.

If you want to read more about it, check out this post.

Your gear is of importance when playing BAP and EASHL. If you're a defencemen you might want to choose a stick with a flex and curve that makes your shots harder and lower (good for deflections).
When it comes to the skates the radius of the blades affects your agility versus your speed.

There's a good article 'bout this at operationsports.