The qemu-kvm ebuild (1.0.1 and 1.0-r3) set up a variable called conf_opts but doesn't actually pass it to configure. This makes the static and debug USE flags ineffective.
You may need to remove the static option or make it possible to build without system targets. I simply couldn't get it to build without doing it manually for just linux-user targets.
I've corrected this issue and I've blocked static from being built with ALSA since Gentoo's ALSA always requires shared libraries. The fix is in 1.1.0