What is new in Ubuntu 11.04 (Natty Narwhal) Desktop
Unity is now the default Ubuntu desktop session. The Unity launcher has many new features, including drag and drop re-ordering of launcher icons, full keyboard navigation support, launcher activation through keyboard shortcuts, right-click context menu quick-list and switching between running applications.
The Ubuntu One control panel now allows selective syncing, and the launcher icon now displays sync progress. File syncing speed has been improved as well.
The Ubuntu Software Center now allows users to "rate & review" installed applications, share reviews via integration with social networking services added into Gwibber, and has other usability improvements.
GNOME programs now use a new scrollbar which takes less screen space.
Ubuntu 11.04 comes with the latest Firefox 4.0 as the standard web browser.
LibreOffice 3.3.2 has replaced OpenOffice.org in 11.04 as the default office suite.
Banshee 2.0 has replaced Rhythmbox is the standard music player, and has now been integrated into the sound menu.
Improved Underlying Infrastructure
11.04 has a kernel based on mainline branch stable kernel 188.8.131.52. Some of the highlights include upstream acceptance of AppArmor, support for Intel IPS (Intelligent Power Sharing), removal of the Big Kernel Lock, file system improvements to Btrfs, Ext4, and XFS, and of course the usual driver updates and support for new hardware.
X.org 1.10.0 and Mesa 7.10.1 are the new versions included with 11.04. The X server includes a prototype of the multitouch input extension (XInput 2.1). The Qt toolkit also includes pre-release support for multitouch.
The GNU toolchain has transitioned to be based off of gcc 4.5 for i386, amd64, ARM omap3/omap4 and PowerPC architectures.
All main packages have now been built and and are installable with Python 2.7.
dpkg 1.16.0-pre brings us up-to-date with staged changes for the upcoming Debian 1.16.0 dpkg release, as well as pulling in the current version of the in-progress multiarch work.
Upstart has been updated to 0.9.7-1. There are a lot of new features: it is now "chroot-aware", there is support for basic job/event visualization, there are two new initctl commands (show-config, check-config), a socket bridge is now provided, the latest D-Bus version now allows D-Bus services to be activated via Upstart, a manual job configuration stanza, and override file support is now available.