Honu - I believe that if you make reservations with an 'old' PointStretcher certificate the current value will apply. But I don't think that's the case if you only order the certificate without the reservation.
Sorry, I didn't seem to be able to find out anything about your hotel questions.
UpInTheAir - The PoinStretcher booklets for the second half of this year should be sent out with the new Hilton booklets pretty soon. You might want to check at
www.hilton.com too because sometimes they're ahead.