Server

Tons of sites have already announced it, but the links are not always easy to find, so here are the direct links:

Most of the users out there just need the "Five Language Standalone" version: x86 x64

To read what is new in SP2, go here.
To read what hot fixes and security fixes are included, go here.

Due to Server 2008 R1 and Vista sharing a common code base, the above links are for either Vista or Server 2008 R1.

Don't forget to reclaim hard drive space after installation with compcln.exe.

This is one of my favorite new features of Windows 7 and Server 2008 R2. Replace VPN in your enterprise with DirectAccess but still enjoy multi-factor authentication.

Wondering how to set it up to try it out? Download the step by step guide!

The official description:
This paper contains an introduction to DirectAccess and instructions for setting up a test lab to demonstrate DirectAccess with a simulated Internet, intranet, and home network.

DirectAccess is a new feature in the Windows® 7 and Windows Server® 2008 R2 operating systems that enables remote users to securely access intranet shares, Web sites, and applications without connecting to a virtual private network (VPN). This paper contains an introduction to DirectAccess and instructions for setting up a test lab to demonstrate DirectAccess with a simulated Internet, intranet, and home network using the Release Candidate versions of Windows 7 and Window Server 2008 R2.