Hoping for:
USB 3.0. Seriously, many USB 3.0 peripherals and flash drives out there. TB deployment is not moving quickly. It's hard to imagine there would be a TB flash drive anytime soon.
SSD that is not a blade (mSata) SDD. If the MBP is slightly larger than the MBA, space should be no problem. They'll be many more choices for SSD and for upgrades if things aren't restricted to blade SSD's.
Better screen-higher res and anti-glare. Retina display is too much to expect, but more pixels.
Improved battery capacity. With optical drive going away, there'll be space. But there's a tradeoff between battery size and keeping the MBP weight low.
Retaining 1 Firewire port in this model, for backward peripheral compatibility.
It is a MBP-it should be more versatile than the MBA.
That and the only place you can get TB cables is Apple... **** proprietary cables. Or Amazon for a *$2* discount.