Asset Changes in v3.0
Craft’s assets functionality is getting refactored in Craft 3, so anything you do with those APIs today will need to be updated when 3.0 comes out.

The silver lining for you is, literally every plugin will need to be updated for Craft 3 (due to us moving to Yii 2), so we are planning on having a several month-long beta period where we will work with plugin developers to get their plugins updated, before the official public release. So we will be happy to work with you on updating your plugin during that period.

As far as an ETA, I couldn’t say. Craft 2 still has a lot of shelf life ahead of it.