Naw, that's his dad definitely. ^^
Check out his hair.
Plus, Kakashi refers to him (in the accompanying spoilers) as "Dad" or "Father" or whatever.
There are two possibilities here:
1. Kakashi's hallucinating. xD
2. He can communicate with his father through something having to do with the White Fang Chakra (like, they're linked, or Kakashi's dad is imprinted into him or some crap like that)
Either way, this shows Kakashi is conscious.
That means he's not dead yet! :D:D:D
He's hanging on, and his talking with his dad inside of him probably has something to do with the White Chakra. It'll probably give kakashi a major boost in his chakra, he'll get all better immediately, and beat the crap out of Pein.
Sort of like how Naruto talks to the Kyuubi.
So, Kishi's using this as a way to tie up any questions we still have about kakashi (MS, etc.), and then Kakashi will die, or he's using this as a cliffhanger at the end of which Kakashi will live.
Kakashi will most likely live after this, I don't think Kishi would be so cruel as to give us false hope about kakashi >.< I mean, Jiraiya didn't have some cool talk with his dad before he died.
And that's not what Kakashi looks like under his mask.
Kakashi's like.... 24? I forgot his age.
His dad would be in his late 40's.