One of the new features for TFS 2010 Version Control is the ability to rollback or undo a changeset or check-in inside the product and see it as a new pending change type (and new change type in the history) inside Team Explorer.  This feature has been available in TFS 2008 but you had to use the TFS Power Tools.  The only gotcha for the TFS 2010 implementation is that you have to use the command-line application tf.exe to actually perform the rollback information.  More information about the tool is available here in the MSDN Library:  http://msdn.microsoft.com/en-us/library/dd380776(VS.100).aspx

The syntax is:

tf rollback /changeset:changesetfrom~changesetto [itemspec] [/recursive]
            [/lock:none|checkin|checkout] [/version:versionspec]
            [/keepmergehistory] [/noprompt] [/login:username,[password]]

tf rollback /toversion:versionspec itemspec [/recursive]
            [/lock:none|checkin|checkout] [/version:versionspec]
            [/keepmergehistory] [/noprompt] [/login:username,[password]]

Versionspec:
    Date/Time         D"any .Net Framework-supported format"
                      or any of the date formats of the local machine
    Changeset number  Cnnnnnn
    Label             Llabelname
    Latest version    T
    Workspace         Wworkspacename;workspaceowner

Ed Blankenship