It is weird that those kernel-modules are failing to load, but that may be because they are compiled in. I am rather clueless now about those issues, so I would at least give the generic kernel a try.
Also, with older kernels (around something like 2.6.30 this issue was resolved) I had to use acpi=off on my laptop, this of course gave issue with power-saving. With some poking around I realized that the only option that was needed was nolapic, which let all the power-savings working, maybe trying a few different options is a worthy try. Some shots in the dark, but may be you have the time to try.
If that all is not working may be it is the simpler solution to go for a cheap discrete video card.

I'll experiment with boot parameters and a different kernel. I can also reload the older BIOS. If others are successfully using the same Intel chipset with Slack-current then it's probably a board specific (BIOS) problem.

Thanks.

I finally got the i915 driver to load after installing the 3.3.4 kernel. I used Slack -current from May 5th with most of the Slack "generic" config settings in the 3.3.4 kernel compile). With this kernel the "acpi=off" boot parameter is NOT needed and the Intel driver loads easily (along with some other monitoring drivers).

Apparently ACPI is needed for the graphic driver to load ... at least on this motherboard.

The "heaven" benchmark loads but still does not work. It does now identify the GPU as the Intel Sandybridge.

X loads the intel graphics driver automatically without xorg.conf needed.

glxinfo shows Sandybridge hardware in the OpenGL renderer string.

lspci shows the i915 is the kernel driver in use. All good signs.

Note that glxgears shows exactly 60 fps. As others have said, don't use glxgears to determine if hw acceleration is working.

I set "vga=ask" in lilo and the game "extremetuxracer" gives around 20fps if a vesa mode ('l' 1920x1080x32) is used on boot and gives around 60fps if a vga mode ('0' 80x25) is used on boot. I wonder if this a reasonable rate or should the built in Intel graphics chip be able to do better?

I was surprised the this video mode setting in lilo impacts the graphics later in X Window.