The biggest and best solution to this problem is to STOP CHARGING NON FFs FOR THE FIRST BAG TO BE CHECKED.

After the implementation of the "no liquid rule" the overhead space was always wide open. There was plenty of space because a big percentage of people didn't want to mess with ziplocks and such. When the airlines started charging the masses for checking bags all of a sudden the bins filled back up again. Make the cases free to check and then most won't be up in the overhead bin to start with.

Also -- from what I have read the 787's WILL have seat specific slots for bags.

My biggest pet peve is the oddities between different jet's bins. My bag slides nicely into a DC-9, but I have to lube the sides up with crisco to get it in an MD-88. Also sometimes it will fit wheels down and out, but other planes it has to be wheels in, upside down. It just depends.