Let me begin by stating that the intelfb driver is very old already. And there are issues. Mode setting with "non-CRT" devices usually fails:
intelfb: Non-CRT device is enabled ( LVDS port ). Disabling mode switching.
intelfb: Video mode must be programmed at boot time.
So you need to set the mode very counter-intuitively via the vga kernel commandline. To do that, you need to know the mode. Especially on 64-bit systems the only way to find it out is sudo hwinfo --vbe.
Now you can use a kernel command line like video=intelfb:mode=1280x800 vga=0x0362 and the system should boot with the chosen resolution. Even if you're using a laptop like I am.
This will not work with a kernel earlier than 2.6.28-rc1 from my experience, but maybe you're lucky. If nothing happens, try the newest kernel. And of course feel free to comment in any case. And I think this works only if the intelfb module is compiled-in, not if it's compiled as a module, as it usually is in distribution kernels.