Just read this at Gaf:

From the Ubisoft investor meeting today: "What is true is that three months ago when we announced our results, we were kind of referencing that we, in our plan, we had built up Watch Dogs with expectation slightly below what Assassin's Creed 1 did when it was first released--and it was 6.2 million," a Ubisoft director said. "So after E3, what we said today was that we do feel that we can expect…slightly above the 6.2 million that Assassin's Creed did."

It's achievable since the game will be on 6 platforms.

Really? I mean the game is releasing on almost every platform available so it's definitely possible. But giving that this a new IP the risks are much higher. The game looks solid so I don't see why they can't reach it. 

It always makes me nervous then companies expect new IPs to sell a lot.  I hope they don't can Watch Dogs because it doesn't reach that 6.2 million mark.

Pretty safe bet in my opinion.

Given the reach this title has with respect to platforms, I think it is certainly possible. If it gets good reviews and the right marketing then I see no reason why not.

And it will. That .2 may be for Wii U.

given how amazing the game looks... i think it will be very achievable. still, those are pretty big expectations for a new ip and quite a gamble (at the greenlight meetings when the game was just a concept).

Well what is that.. a little over a million a platform.. and is this launch or lifetime may I ask?? Lifetime sure.. Launch.. not so much... they are in for a grave disappointment if they are expecting it at launch.. still... yes 6.2 million is doable..

Seems reasonable. It's got a lot of hype and looks like the next big IP. I know I'll be getting it.