One of the earliest standalone rumors we heard was that a young Han Solo would be the focus of one. In the spirit of everything old being new again, Making Star Wars says that may indeed be the case – well, the Han part at least – and that filming may “eventually overlap” with Episode VIII. Also looking to be attached to the spin-off in some fashion, though not necessarily as Han Solo? Aaron Paul.
The previous Solo rumor fell out of favor after we heard Kathleen Kennedy say that spin-off characters wouldn’t be “in and out of the saga episodes.” That doesn’t necessarily preclude the films dealing with Saga characters before or between their Saga appearances, but in any case – plans can change.