Previews of upcoming versions of MonoTouch are available when you select in MonoDevelop the Alpha channel. Depending on the release cycle, updates on the Alpha channel will only be available if your system contains the proper Apple SDK installed.
For example, the April 15th 2010 preview of MonoTouch required Apple's confidential iPhoneOS 4.0 SDK, so the packages were only installed if you had both selected the Alpha channel in the MonoDevelop Updater and if you also had installed iPhoneOS 4.0
Follow these steps:
The May 6th, 2010 preview of MonoTouch contains support for iPhoneOS 4.0's new APIs up to 4.0 Beta 3. It requires the iPhoneOS 4 Beta 3 SDK as provided by Apple.
In addition to the SDK, you also need the latest version of MonoDevelop from the Alpha channel (MonoDevelop 2.4 Preview) which supports developing both applications for iPhoneOS and the iPad.
The full listing of the new APIs available on iPhoneOS is available as part of the Preview MonoTouch download and is available in your system in this file (copy and paste this url into Safari):
Changes from the stable 2.0.2 to the 3.0.3 preview:
file:///Developer/MonoTouch/usr/share/doc/MonoTouch/api-diff-2.0.2-to-3.0.3.html
Changes from the 3.0.2 preview to the 3.0.4 preview:
file:///Developer/MonoTouch/usr/share/doc/MonoTouch/api-diff-3.0.2-to-3.0.3.html
This release is called MonoTouch 3.0.4 (the release notes with the 3.0.3 version were prepared before the final release number).