I see that they are going to sell a version with Windows 8.1 Professional for business customers. It isn't listed on the Microsoft Store web site yet.
http://blog.surface.com/2015/03/announcing-surface-3/
This means you will be able to join work domains and use Bitlocker with that version. I assume the Surface 3 has a TPM chip since most new tablets and even the $199 Asus X205TA have TPM chips now.
I would hope it will be much cheaper to buy the business version than to buy a $99 8.1 Core to 8.1 Professional Pro Pack upgrade and it would save the hassle of having to manually upgrade and then have to do t again any time you do a factory reset.
At $499 it's $300 less than a Surface Pro 3 i3, but the Pro has Windows 8.1 Pro included in its price, 4GB RAM and a bugger screen.
I will have to see one in person to see if the 10 inch size is big enough. Even if the smaller screen isn't an issue, the smaller keyboard that comes with it might be too cramped. In the past, I have found 11.6 to be the tiniest size laptops that have usable keyboards for me.