Oracle released Solaris 11 11/11. The documentation says:
Oracle Solaris is the #1 enterprise operating system providing industry leading availability,
security and performance on both SPARC and x86 systems.

Ok.. it is the only os, which runs only on SPARC and x86 systems. Just kidding ;-). Here the key features listed in the official documentation:
• Automated Installer
• Image Packaging System
• Oracle Solaris Zones
• ZFS File System
• Simplified Administration
• Designed-in Virtualization
• Scalable Data Management
• Advanced Protection
Here my favourites:
I/O Enhancements to netcat
netcat, a popular utility used for network observation and debugging, has been enhanced to include a number of command line options that allow administrators to configure a number of previously hard coded values related to I/O and integration with zones, along with a number
of usability additions to improve familiarity with netcat on other operating systems.

Default Shell
bash(1) is now the default shell for new users added to the system using useradd(1M) command line utility if another alternative shell is not provided, and the default shell for new installations. ksh93(1) is used as the default system shell.

Resetting System Configuration
A new utility, sysconfig(1M), for unconfiguring and reconfiguring an existing Oracle Solaris 11 system has been added to replace the legacy sys-unconfig and sysidtool utilities. This tool can be used within the global zone and non-global zones to configure a set of pre-defined groupings such as system identity, network, users, naming services and location/time zones. The tool can be run interactively, using the System Configuration Interactive Tool, or in a hands-off manner using a system configuration profile.

Changing MAC Address with dladm(1M)
Support for changing the MAC address has been added to dladm(1M). Unlike changing the MAC address using ifconfig(1M), this is a persistent change across reboots, and changes the primary MAC address used by all current and future MAC clients of the underlying data
If you want to find your own favourites, just read http://www.oracle.com/technetwork/server-storage/solaris11/documentation/solaris11-whatsnew-201111-392603.pdf...


Openafs: Version 1.7.1 Client for Windows

In september 2011 openafs.org released a new windows version (1.7.1). In this version the following features were changed:
  • OpenAFS is a native Microsoft Windows file system.
  • Significantly faster than the OpenAFS 1.6 release (up to 800MB/second
    read throughput from Solid State Disk backed cache)
  • Does not require the installation of the Microsoft Windows Loopback
  • Provides support for kernel enforced Process and Thread Authentication
  • New Explorer Shell integration including AFS specific property sheets
  • Immediate access to \\AFS namespace after
    system resume
  • AFS Mount Points and Symlinks are File System Reparse Points
These features simplify the usage of AFS! First you do not have to fear windows updates, because of weird changes in some samba routines. Second: AFS really works after standby/suspend to disk. Even working in networks with no access does not require a restart of your afs client...
If you are still working on pre 1.7 releases: UPGRADE!!!
But do not forget to install MIT Kerberos for Windows. This is for 1.7 recommended...