Hi.
Just let you know that, at least for the intel driver (and provided your card is capable or opengl 3.x) Excel won't fail to start anymore.
After compiling latest libdrm, mesa and xf86-video-intel I have been using Excel 2013 in Gentoo with some rather complex sheets. There are rough edges for sure, and I long for the day that copy/pasting from this to thunderbird/linux will work decently with images and that stuff. But, generally speaking, it works.
I guess this is not the right way to report it but I found no other.
Cheers.