Hi David.
I use the latest git tree as well as 2.6.35, 2.6.32 (both ubuntu lucid) and various 26-rc candidates with the same problem on Dell E4310 laptop: screen blanks when getting to X start. System works ok, but without screen (switch to text console does not help).
If I add 'i915.nomodeset xforcevese nomodeset' screen still blanks but kernel panics. Unfortunately I can not connect it to any other computer to get netconsole dump.
If I add 'i915.nomodeset xforcevese nomodeset single' kernel command line then X can be started 'manually' in a failsafe mode (there is a ncurses screen in ubuntu for that).
I read a lot of internets about this problem but neither solution helps in my case. I added a small debug to intel_dp_link_required(), which prints some params, namely whether device is edp/pch, pixel clocks and returned value for the case when both edp and pch are set, which is not the case for my hardware: pch is not set.
I attach dmesg and X log for successful failsafe start, hope it will help.
Thank you.