There are a couple of useful powershell command-line tools that are of use:
This is useful to query tasks and work items
tfpt query “ProjectPath to query”
From a mapped folder allows the running of existing tfs work item queries from the command-line
It uses the current folders mapping to identify the project.
This is useful for quering checkins:
Run from the VS2012 command prompt:
tf history x:path_to_project /recursive /noprompt /user:”My User Name”