[Standard] Spirit Slam! (U/W Spirits)[Feedback/Suggestions]

Title says it all. This is a Standard built U/W spirit aggro deck. I need feedback and suggestions on how to improve it. I've played my friends' FNM decks and it can hold it's own against most of them, but sometimes can have a little trouble against U/R Delver and Haunted Humans. Anyhow, here's the link, I await your comments.

http://www.mtgvault.com/ViewDeck.aspx?DeckID=296371

EDITED: Revisions