Let me report my recent progress.
I have finally got a DP->HDMI adapter:http://h10010.www1.h...F...ng=en&cc=us
And gladly found, that the graphics bundle extracted from 10.6.7MBP or 10.6.8Beta does allow to use mobile HD3000 with "AAPL,os-info" fix discovered by Kyle_C -- via external connection.
Concerning the internal one (most likely using LVDS) I am 99% sure, that the problem is caused by the same 20h magical bytes from MBP8,1 ioreg. It seem to hardcode display port layout: just #0 and #5 (types 0x2 and 0x400 respectively) regardless of the actual hardware.
In my DSDT the 1st device inside GFX0 is denoted as CRT0 in DSDT, while the 2nd is marked as LCD. I do have a problem with port #0 behavior under SL 10.6.x -- both internal LCD and VGA D-Sub show garbage, nevertheless, EDID of internal LCD is determined correctly, native resolution selected and shown in System Profiler.
"AAPL,os-info" might force 10.6.x driver to treat both 1st and 2nd ports as #0 -- in my case, since Kyle_C does not report the same problem.
The 3rd device (DP0) in DSDT does work perfectly via DP->HDMI or DP->HDMI->DVI connection to external fullHD panel -- if and only if I select the 3rd port as default in BIOS.
So, I would recommend selecting external port as the default one in BIOS for those, who need external connection on laptop. I believe that the "connector-type" 0x4000 of port #5 should not prevent proper detection and operation.
I suppose that 10.6.x version of AppleIntelSNBGraphicsFB.kext was not intended to be "rather general" (i.e. to be used with future MacBooks and Mac mini). It might not check the real hardware, just relies on "os-info". There is a property "overried-os-info", but it does not seem to work, at least in the way I hoped -- "ignore os-info and use EDID/DSDT instead".
The above stated assumptions are based on the fact, that both 10.7 DP3 installer and a driver bundle taken from 10.7 DP3 works perfectly both with internal LCD and an external one via any of my digital connectors (did not try CRT0/D-Sub). As it was reported by bcc9, 4 connectors are detected by driver bundle: #0, #5-7. In fact my DSDT contains 5 devices in GFX0 section, not 4: CRT0, LCD, DP0, DP1, DP2. So it also looks like a hardcoded layout, but simply a better one.
And as reported by Kyle_C, OpenGL framework seems to be heavily modified in Lion, my attempts to overcome filename mismatch reported in system log and force framework loading by using symbol links did not help a lot. I would not expect QE/CI support with 10.7 drivers under 10.6 Mac OS. If anyone succeed, please let us now here.
Long story short: those people, who need QE/CI with HD3000 urgently could try:
1) to use "os-info" trick in com.apple.Boot.plist with 10.6.7/10.6.8 HDGraphics bundle on SL -- it should be ok with external port, but may not work with internal LCD on laptops. This configuration appears to be limited to 2 ports only. You may be required to select the desired external connector as the default one in BIOS.
2) to use 10.7DP3 bundle -- it is a fast and simple way to get native resolution and 4 ports, but no QE/CI.
In case you have a problem, try "ioreg -lwo0 | grep EDID" and compare with other source (monitor-edid under linux liveCD, etc.) -- in case EDID is not detected properly, use /System/Library/Display/Overrides/ to provide correct EDID.
Those who can wait for a few months, please be aware, that forthcoming 10.7 release might definitely support you HD2000/3000 out of the box.
UPDATE: an issue with lion kexts (on 10.6.7) discovered: when I use a single 2GiB DDR3 module (288MiB allocated for graphics) -- no artifacts at all. With the second module installed (384 MiB reported to be reserved for graphics) -- some gray artifacts appeared on first restart. BTW, the same module was working for half-year without any issues in another laptop and it was the only module in that system.
FINAL UPDATE: for those people, who have an issue with internal LCD/VGA, thus, unable to use 10.6.7MBP kexts: you should not replace AppleIntelHDGraphics*, just take AppleIntelSNB* from 10.7 -- and then you get full QE/CI/OpenGL without artifacts at all.