I must say, that sounds pretty awesome...I had a B-3 with two Leslies for many years, and Korg really has that sound nailed with their new BX-3.
I also believe that having it played through a real Leslie (as in the video) makes it even better than through it's own rotary simulator, although the latter is more than okay.
A friend of mine has an original Korg BX-3 from way back in the 80's, a relatively rare instrument today (they also made the more popular single manual CX-3) and when it is played through his Leslie 147RV (actually one of my old ones) it is surprisingly close to the Hammond (not so much with it's own rather dated simulator).
Here's an old BX-3 demo (there may be better ones) played through a Leslie 760.
http://www.youtube.com/watch?v=QyMcSnNsAPw The new Korg BX-3 also sounds some sweet and Hammondy through the Neo Ventilator Rotary simulator.
http://www.youtube.com/watch?v=2mJ5W1xr1o0 They make great gear.
Ian