Hearthpwn

This seems suspiciously comparable to Velen's Chosen, an extremely good card.

Will spirit raptor have +1 spell damage as well?

Any idea?

Yes. This works like all the other mounts.

This is great for burn shaman!

What are the stats of the spirit raptor and are there any additional abilities like the one in battlegrounds?

This is a mount. All "mount" cards work the same - they apply a buff to a card and a deathrattle that summons a minion with effectively the same text as the buff. In other words the spirit raptor is a 1/2 with "Spell Damage +1". 

This hasn't been confirmed yet as far as I know, but I'd be extremely surprised if they randomly decided to break the pattern with this card for no reason.

Y I see. I missed the mount (let's say) code word when released and came back to the game like a month ago. I saw from playhearthstone it is indeed the stats u described. Thanks for the answer in any case :)

Mount cards are generally just good. 2 mana for +1 spell damage is good and this is sticky. Shaman has a lot of ways to exploit this.