Here is some information from the Microsoft lifecycle page for WSS 3.0:
WSS 3.0 and MOSS 2007 SP2 has been released on April 28th, 2009.
Based on the above listed information support for SharePoint servers without SP2 will end on April 28th, 2010. Be sure to evaluate Service Pack 2 now if you have not yet done and ensure to install it before the deadline.
As we had some support cases on this in the past: be sure to install SP2 not only for WSS and MOSS but also for all installed language packs for these products.