While I don't have a formal dining room myself - and I love my open space - occasionally I wish I had a space to serve meals that's hidden from the kitchen. Not so much because of the food prep stage as to get away from the dirty dishes when dinner is over, but everybody's still hanging out. I never do the dishes right away...and I love sitting around and drinking wine and talking at the table.
With that in mind, I've been checking out formal dining room options (for other people. We are not redoing our house ever again):