Hi,
please, please rename all class extension in a way that they can be identified as being part of playMaker, e.g. rename Vector3.AlmostEquals to Vector3.pmAlmostEquals.
It's a pain to code some stuff and notice later on that you've used methods not part of the base Unity libraries. Marking them to be part of playMaker (minimum is a proper Intellisense documentation, renaming is better, both is best!) really helps and is a good and friendly coding style.
To smooth the changes for users you could flag the old extensions as obsolute and remove them one or two versions later.
Jake