RC delegation will be possible using the posting key authority. And most users that use ecency or peakd, etc... have allowed posting key authority to these UIs. Like you for example:

Nothing to be afraid of, because these are trustable accounts that will not use your authority without previous consent from you. But effectively an account with authority to broadcast transactions can use the same authority as your posting key (in this case) without you authorizing anything with your real private key (the key is not known to them) (and only while the authority is permitted).

They could if they wished, delegate RC to other accounts. So, what I see going forward is (and this my speculation only), ecency or peakd asking users to tick a box if they would like to help new users with RC delegation or not, in exchange for whatever they see as a good tradeoff.

Probably there will be "donations of RC" too?... not sure. I will probably run some giveaways of RC too...