Here is the announcement post.  To be honest, the code for xf86-video-mga really should not be released at this point, but due to various reasons, I feel like it needs to ship out at this point.

• There has not been a new release for a while (almost 2 years)
• Already started the new release process
• Rendering issues with EXA affecting some models were fixed

Just for disclosure, the code is currently broken with Millennium, Millennium II and G550.  For Millennium and G550, it appears that whoever wrote the EXA code completely broke the code for those devices. (i.e., segmentation fault)  Perhaps, disabling acceleration might workaround the issue for now. (did not have the time to experiment)  As for Millennium II, the rendering is completely messed up, so the code is completely useless.  I tested both PCI and AGP versions for Millennium II and G550, and the results are the same.

What this means is that this version’s code works mainly for G200, G400, and G450 at this point.  I do not have access to Mystique and G100 at this point, so the code is untested on these models.