With 3.5M6, there are zipped repos for the RCP, CVS, JDT and PDE (Runtime and SDK) zipped p2 repos available with each build.
These zipped repos can be either used to provision your install or used to provision your PDE target.
These repos have a format like this artifacts.jar content.jar plugins/ pluginA.jar pluginB.jar pluginC.jar features/ featureA.jar featureB.jar
Thus these zips cannot be just unzipped on top of your install or into your dropins folder. You must use the p2 user ui to untilize them.
Provisioning your install from a zipped p2 repo
To provision your install, select Help->Install New Software and select Add to add a new repository
Select the archive that you have downloaded from the build page. For example, if you wish to provision from the M6 jdt source zipped repo
Select Open. You'll see the contents of the repository, identical to one on a remote http repository.
Proceed as normal to provision your install.
Provisioning your target from a zipped repo
When setting your target, select Add and select Repository or update site
Select Manage Site
Select Archive and proceed to select the zipped archive on your filesystem.
Note: Please see bug bug 268210 for issues related to provisioning from these repos for your PDE target. Currently, you can't provision from these repos in PDE because the repository browser doesn't show categories.