Spanish Windows enthusiast site Muywindows has published screenshots of a Pre-SP1 build circulating within Microsoft that, according to the post, will be handed out to select testers some time in July. SP1 at this point contains a wide array of updates (around 150 according to Muywindows), some important, critical, and optional, and some bumping up your build tag (currently, the build tag is between 7600.20500 and 7600.20700).
In other SP1-related news, after clarifying with our sources we can confirm that the post-RTM build strings we reported on a short while ago (
http://www.windows7newsinfo.com/smf/index.php/topic,5799.0.html) are in fact SP1, and not Windows 8. SP1 is expected to officially launch some time around Q4 2010, which is just over a year since Windows 7 hit the GA stage of its development on October 22nd, 2009.