Hearthstone Arena

[SevenSpirits]

They're asking to not post about this on high-traffic places like the hearthstone subreddit yet since they wouldn't be able to handle the server load, but http://www.heartharena.com/ is up and it's pretty sweet. It's basically a drafting assistant - you tell it your options for each pick and it scores them for you based on a base list of values and a ton of other factors regarding what you've already picked. I think it's a really good basis for learning how to draft arena well.