Right now, 3 Microsoft Stores already have HTC Vive demos ready for potential customers to experience. These are at New York City, Washington state (Bellevue Square) and Utah (City Creek Center). By the end of next week, 2 more will be added and peak at least at 30 by the end of the year. The other place where you can try out a Vive will at various GameStop locations. The plan is for 10 stores by the end of the month but how many there will be at the end remains to be seen.
For now, we have no idea what kind of demo the Vive will have at these locations. They should be smaller than the room scale demos at Overclockers UK but the idea is the same, to get VR out and into public view. Customers will also be able to order/pre-order the Vive at the locations. You can find out more about the Vive here.