On the second Tuesday of every month Microsoft releases a series of system and security updates, thus the 2nd Tuesday of the month is referred to “Patch Tuesday” in the IT world. Next Tuesday is particularly note worthy. See the article from Network World.
http://www.networkworld.com/news/2010/060310-microsoft-plans-gigantic-patch-tuesday.html?source=NWWNLE_nlt_daily_am_2010-06-04