The Park Lane currently has some rewards reservations available during the Olympics. They appear to be non-refundable, due to the event.

I was very happy to be able to snag three nights on the weekend of the 3rd to complement the County Hall reservation I have for the end of the event (we'll be in the Cotswolds with family the rest of the time).

I don't know if this signals that other hotels will be adding rewards rooms as their blocks close. I would have liked to hold out for one of my favorites, but felt it was too risky to pass this up.