One of the things that Microsoft did with the release of VSTS 2008 was to relax the TFS licensing to enable a number of use scenarios. Specifically they now "allow an unlimited number of users in your company to create any work item, query for work items they have created and view or update any work item they have created all without a CAL." Brian Harry provided the details in his blog post "TFS Licensing Change for TFS 2008"
The relaxation of the CAL licensing was great news but unfortunately there was no user interface that could enforce the limitations of creating and viewing only your own WIs. That where the newly announced Work Item Web Access (WIWA) Power Tool CTP comes in. This cut down version of Team System Web Access (TSWA) allows you to expose a web interface that automaitcally enforces compliance to the "only view and edit work items I create" restriction.
WIWA differs from TSWA in the following ways show in the following screenshot. There is only a single query wich is "Work Items created by Me" and the tabs you are familiar with from TSWA such as Documents, Reports and Builds are missing.
The CTP of this power tool is available at "http://www.microsoft.com/downloads/details.aspx?FamilyId=FAED8359-F54D-480E-8A86-F154D3DEA07E&displaylang=en%20".