Just random idle predictions:

The 40-story Devon Tower will be filled and will be the most significant building downtown.

The FNC will be completely renovated and will be the regional HQ of a bank not currently in OKC.

Some company will have bought the current Devon tower for their HQ. It will be full of employees.

All of the current housing developments will be finished and full, and there will be one new mid-rise residential tower built from the ground up, either near the Civic Center, or somewhere in the Triangle/Deep Deuce area.

There will be at least one major addition to Bricktown, and there will be more retail.

Core 2 Shore will be mid-way through completion. The new convention center will be finished and there will be a 25 story high-end hotel as its anchor. Lots of construction in this area in 10 years.

The NBA will be thriving, the practice facility will be on the Broadway Extension or the Kilpatrick Turnpike area.

There will be actual light rail plans on the drawing board but they will not have begun construction yet.

The boathouses will be finished along the river, and there will be significantly more landscaping and cultural improvements.

The sprawl will continue unabated to the North and Northwest. Edmond, Deer Creek, and North OKC will have completely grown together.

Chesapeake will have fully built-out its campus and completed renovation of Nichols Hills Plaza. A high-end department store not currently in OKC will be its anchor.

All of these predictions are assuming that oil and natural gas remain strong and that, in addition, OKC has continued to diversify its economy. I would love to see some new large-scale corporate HQ operations, but feel it is more likely that growth will come organically from what is already in OKC and from developing clusters like biotech/medical and aviation.