Ok, I'm going to take a shot at this. My number probably won't be right... but others can correct it. :)

3 -- Hilton Garden Inn (Bricktown)
1 -- Canal extension by Land Run Park (Bricktown) -- or is this down now?
1 -- Hilton Inn Express (Bricktown)
1 -- Maywood Apartments (Deep Deuce)
1 -- The Edge Apartments (Midtown)
1 -- Main Street Garage (CBD)
3 -- John W. Rex Elementary School (Film Row)
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11 total

This is obviously only in the urban core, not the whole metro area.

And of course, there's more construction going on than just this. The Aloft hotel is still chugging along, but it's topped out and scaffolding is up, so it doesn't have a crane anymore. And other new buildings, like KD's restaurant and 430 Lofts, aren't tall enough to need cranes.