How often do you have guests in that guest bedroom anyway? Why can't it be TWO rooms at once?
The truth is as follows: the guest bedroom isn't part of society any more. Most of our friends are nearby, or are talking to us via the Internet. Nine times out of ten, any visitors are either staying late and sleeping in their own beds after driving home, or would be perfectly happy to sleep on a comfy comfy air mattress that you set up in front of the TV. And, incidentally, a home theater would look great in the space that used to be your worthless "guest bedroom" that goes unused like 95% of the year. Wouldn't it?