I'm pretty sure I read that the enterprise pack that includes VPN won't be out until 8.1 next year.
The main thing I'm looking forward to is the merging with Windows RT, especially with regards to app development and the stores. This is critical to the success of both platforms and should really be a top priority for MS.
I agree with you fully, I see WP and RT becoming one in everything but branding, the phones will still say "Windows Phone" but at the OS and API level they should be the same. At that point I think RT can finally drop the desktop on tablets, though I think they can do it with 8.1. Maybe not totally get rid of it quite yet but hide it away so only the power users can access it if they want it.
Once we can have phone and tablet apps that are the same and on the same code 100% with one unified store then I see no reason why both device types don't see a bigger boost in sales. The phone is already picking up and if it can kick start tablets with RT as well then we could find ourselves in a cycle where they both go hand in hand. People who have a phone and like the apps/games on it that could get the same on a tablet are likely to buy one when the time comes, and vice versa as well.