Thierry Reding, the developer at Avionic Design that's responsible for this Tegra DRM Linux graphics driver (read The Back Story On The Open NVIDIA Tegra Driver), published a set of seven patches this morning that provide various enhancements to this DRM driver that's in the process of receiving 2D support.
The enhancements include support for two additional hardware planes found on the Tegra, an improvement to yield a speed-up when changing the frame-buffer but without changing the resolution, VBLANK support, a page-flipping ioctl, and a new framebuffers debugfs interface.
The most notable work is obviously the page-flipping support finally being implemented, VBLANK support in place, and now support for the Tegra B/C planes that can handle RGB and YUV pixel formats and can be used for hardware overlays or hardware cursor.
These patches can be found on the dri-devel list and will possibly be merged into Linux 3.9 otherwise the Linux 3.10 kernel.
More details on the current state of this open-source NVIDIA Tegra graphics support can be found in NVIDIA Continues Backing Open-Source Tegra Driver and Open-Source NVIDIA Tegra Becoming More Exciting.