Sometimes pictures speak better then commit messages, so here's the current boot status:
http://www.tinykrnl.org/ros_by_ntldr.png
It fails because our Memory Manager early-boot initialization depends on some freeldr information. If I can/have time, I'll try to make it not depend on them, and/or use NTLDR structures instead.
Anyways, serial debug printing works and the GDT, IDT, TSS, KPCR are all setup, so this can now be used as a good tool for blackboxing ntldr.