As reported here, some Hilton hotels (the Homewood Suites) are starting a new program where you will be able to see a floorplan of the hotel you will visit, and choose your own room prior to checking in.
This is a great idea if you have particular preferences such as not being near the elevators.
You can find more information about this project at the Hilton Homewoods Suite page here.
I guess it won’t be long to see a website like Seatguru for hotel rooms
Thanks to Upgrade: Travel Better for finding this