Specifically on fixes or new issues on the nMP, since cMP will have it's own such things.
There isn't a new EFI Boot Rom in today's update, it's still MP61.0116.B11, so no fix for the lack of bootscreens with 4K SST monitors.
The strange mirroring bug with dual 4K displays that was introduced with 10.10.2 (I think, might have been 10.10.1) where everything is mirrored until you to turn one of the monitors off and then back on is still present.
Otherwise, everything seems good so far.
There isn't a new EFI Boot Rom in today's update, it's still MP61.0116.B11, so no fix for the lack of bootscreens with 4K SST monitors.
The strange mirroring bug with dual 4K displays that was introduced with 10.10.2 (I think, might have been 10.10.1) where everything is mirrored until you to turn one of the monitors off and then back on is still present.
Otherwise, everything seems good so far.