Now that we have IVersionedID, and IUs extend this interface, there are some places where we can code against VersionedID as opposed to the IU. I'm thinking in particular about LatestIUVersionQuery. This query can now just be LatestVersionQuery, and can be used to find the Latest Version of a "Thing"* in a List (*as long as the "thing" implements IVersionedID) . I would like to make this change after the IBuild as it will help with some of the work we are doing in PDE , but I don't really want to break the M Build. What do you think of Deprecating LatestIUVersionQuery and introducing LatestVersionQuery. Then in our branch we can actually remove LatestIUVersionQuery. This will give people an M Build to move (by M4 the LatestIUVersionQuery will be gone).