The compact framework team has released a beta version of Service Pack 1 for the compact framework version 2.  You can download the packages here: http://www.microsoft.com/downloads/thankyou.aspx?familyId=6548dd53-a418-42d9-a481-19ba3ceca1a6&displayLang=en&oRef=http%3a%2f%2fblogs.msdn.com%2fnetcfteam%2f.  You can read the details here http://blogs.msdn.com/netcfteam/archive/2006/04/21/580901.aspx ; one of the highly anticipated features of this release is the ability to run CF2 applications on CE.net 4.2.  I have one client who has been waiting on this feature for a long time due to a hardware investment that won't allow their converting to CE 5. 

The package contains a Visual Studio patch as well as the standard device updater application.