Benchmarking anything is challenging, but benchmarking your intranet is really hard.  It's likely just not practical for you to conduct multiple site visits to other organizations, and you can only go to so many conferences where other enterprises share their successes and challenges.

Luckily, intranet managers have another option. For the sixth year, NetJMC will be conducting their "Digital Workplace Trends Survey." Last year over 440 organizations from around the world participated and they all received a free copy of "Global Intranet Trends for 2011" (commercial value $750 US).

Interested candidates can apply to participate by sending an email to "[email protected]" with the information requested on this page:
http://www.digital-workplace-trends.com/sign-up-for-the-2011-12-intranet-trends-survey/join-the-survey

You can read what 2010 participants say about the report:
http://www.digital-workplace-trends.com/reviews-of-2010-report/reviews-by-intranet-managers

Key topics this year are:
    Mobile Strategies & Approaches
    Collaborative & Social Aspects
    Search
    Governance & Management
    Business Value
    Future Scenarios