Targeting a release around March/April, the latest Linux Kernel series, 2.6.38, brings some very interesting and exciting new features.
One element that has got quite some attention on the official ANNOUNCEMENT from Linus is the so called wonder patch, which is capable of redistributing CPU load to visibly speed up applications responsiveness. Another Linus Torvalds favorite is the SCHED_AUTOGROUP feature, as well as patches to improve the scalability of the VFS (Virtual File System).
On a different note, AMD's Bobcat processors will get enhanced support, and the DRM Radeon drivers will allow for 2D and 3D acceleration on the HD 62xx to 68xx models. Likewise, we will see experimental features for Fermi chips, including some early 3D support thanks to the Nouveau DRM driver. Support for Intel graphics cards will also improve, this time including better integration with Core-I CPU, which should help get the most from their power saving features. As I said, Linus Torvalds himself was excited about several of those changes, but he stressed out there was something for everyone, regardless of the area of interest.
Ubuntu 11.04 will apparently include 2.6.38 series, so having all these interesting features/enhancements along with the many that come from the much anticipated use of Unity, Banshee 2.0, etc., makes Natty Narwhal one of the most anticipated releases ever.