Wow, didn't realise my original post would cause such debate
Just a thought, the 'vegan' leather thing has gathered pace significantly however, and don't shoot me down for this, Tesla haven't confirmed this is the case yet, assumptions are being made. On the website, it doesn't say it is but it doesn't say it isn't? I know the white seats are definitely 'vegan' but having bought the car just yesterday, the salesman confirmed that the black and cream were all real leather.
Now, not making the case for Vegan leather however, he confirmed it was a lot more durable than real leather and doesn't crack or crease in the same way (I've seen Model S' with black leather and 10k miles with the side bolster already starting to crease).
Given the choice, I think Id still have real leather and based on my purchase yesterday, one of the first in the UK to order the updated overnight spec, this is what I have.
I might be wrong and shoot me if I am, I'll ask my sales guy tomorrow too and come back to you all unless anyone gets better info in the meantime. I don't have twitter though, anyone care to ask Elon to clarify?