We've always had news on The Shield by this time of the year, so we started looking into why Fox hasn't made an announcement for season 6, and the answer wasn't what we expected.
The Shield, which airs on F/X, is a co-production between 20th Century Fox Television and Sony Pictures Television, and for the past 5 years 20th Century Fox Home Entertainment has released the show on DVD. Due to the contracts the companies have, the DVD rights will be moving from Fox to Sony sometime in 2008 (we weren't able to nail down a date). It wouldn't make sense for Fox to release a DVD set and then lose the right to sell it a short time later, so they don't have plans for season 6, and Sony doesn't have the rights to the series yet, so they can't work on it either. Sony will obtain rights to seasons 1-5, and well as seasons 6 and 7. We saw a similar situation when Fox lost the rights to Dynasty after releasing the first season.
We'll keep you updated on the latest in this situation, but for now fans of The Shield shouldn't hold their breath for an early-2008 release of season 6.