Seems likely. The only question is whether it'll be an unofficial arrangement, or whether Charles will become full blown Prince Regent.
Going by the updates we've been given by the Palace there don't appear to be any issues with the Queen's mental faculties, so it might not be necessary given that she could still make decisions.
Also, I expect the Queen is very much aware of how integral she is to public support of the monarchy, so she'll want to avoid giving any apparent confirmation she's on her way out . . .