I got that yesterday, too. Doesn't make a big difference for me; I can typically turn up more surveys by clicking on old "You Have a Survey" e-mails.
Glad to have more surveys, though. My Hilton point balance is looking a little lean and my 5-year old granddaughter doesn't want to stay anywhere else in Chicago but the ORD Hilton where she can see the action at the airport across the street.