Hello. I am Kyösti Mälkki and I will be working on improvements for coreboot debugging tools during my GSoC 2013. My GSoC project plan has some details on things to come, but deliverables and schedule there will be fine-tuned next week or so. All in all, my work here should make it a little less painful to port new mainboards to coreboot and make SerialICE use more flexible.
Some feedback I have already received and the discussion we had on #coreboot suggests that some ARM boards are good candidates to be used for debugging x86 targets. Keep tuned in, the success of my work depends heavily on getting test results from a variety of mainboards.