As discussed by the Office Sustained Engineering group cumulative updates for all Office Products including WSS 3.0 and SharePoint 2007 will be released every second month.
Yesterday we released the so called February 2010 Cumulative Update. It is highly recommended to install Service Pack 2 before installing this cumulative Update
Details and download locations can be found in the blog my colleague Joerg Sinemus published:
http://blogs.msdn.com/joerg_sinemus/archive/2010/02/24/wss-and-moss-february-2010-cu.aspx