There's just under 50 official changes in total compared to the xf86-video-ati 6.14.0 release. The major highlights include Cayman (Radeon HD 6900 series) support when in conjunction with the Linux 2.6.39 kernel (Radeon KMS support is needed; Cayman and newer ASICs will only be supported via KMS), a fix for building against X.Org Server 1.10, Big Endian support for R600 and later with KMS, and various other bug-fixes.
See the 6.14.1 release announcement for full details on changes with source download link.
This afternoon Apple's Jeremy Huddleston has also released xorg-server 1.9.5. This is the last expected point release in the X.Org Server 1.9 series with the 1.10 server now being available and Jeremy will begin taking over the role of maintaining the xorg-server 1.10 stable series. See the 1.9.5 release announcement.