Late last year, I saw a patch go by adding support for the unfortunately common 1366x768 resolution. Some discussion in the resulting thread suggested some possible improvements to the patch that needed to occur before merging; however, I haven't seen a newer version go by. Just wanted to check back about the status of that patch to make sure it didn't get lost.
See also the Launchpad bug about this: https://bugs.launchpad.net/qemu/+bug/1054558 - Josh Triplett