Well as the title says since last night BeOS and basically all old code has been dropped from the Mesa tree. This is creating problems for BSD derivates and Solaris ones already. Will this be affecting HAIKU?
More info here : http://osshed.blogspot.com/2011/08/mesa-kills-of-old-code.html
This isn’t all that big a deal as OpenGL on haiku wasn’t keeping up with the updates anyway… and we aren’t using any gallium drivers yet. However once gallium driver support is working and its pretty clear that is the way forward now that will probably get all fixed up.
Its mostly just a house cleaning effort so old drivers that aren’t getting any new features at all anyway aren’t holding back the new drivers. The BeOS OpenGL support never was officially accelerated anyway from what I understand even though rudolf wrote some pretty fast Nvidia drivers … so may as well write it from scratch to cater to new GPUs.
That said almost all the gpus droped are soo slow it would make you want to tear your eyes out 
… sure they could be faster most likely but noone is interested at all in that since they are 10+ years old. And again! remember many old GPUs are still supported like anything radeon and up… so I think this is a good development I tried the mach64 driver and let me tell you it was aweful even when I could get it to work a cut down version of quake barely ran at its lowest settings at about 8 fps so nothing of value was lost.