It's very hard to place Swinson - the Orange Book didn't spend a great deal of time on women and feminism, and it is on that latter topic she is best known internally.
Her article confirming her intention to stand as Deputy Leader is here:
http://www.libdemvoice.org/jo-swinson-mp-writes-54646.html
Of note is that she actually wanted Farron to stay on.
Anyway - my judgement was always that whoever out of Cable and Swinson confirmed they'd be going for the Deputy Leader role first would decide the actions of the other. The way is pretty clear for Cable to go for the leadership now.
Davey won't be leader. Out of the three remaining likely candidates:
Cable -> Wrote for the Orange Book. An advocate of building a new centrist party in the centre of British politics (and likes a lot of Labour's London people, like Rupa Huq). Probably wouldn't see through a five year term due to his age.
Lamb -> Lost already, abstained on A50 vote. Strong on health and care issues, but seriously lacks charisma.
Davey -> Wrote for the Orange Book. The most ambitious of the three. Probably the least interesting of the three.