I think Guitars will preety much always be about... as for bass may be repalced by the Devil's Left Hand...
I'm not up with the DAW type stuff, but for studio / bedroom bourne music seems a controller can do most things, then add vocals, mublings, vague attempt at monotone rambling rhyming.. what ever is the latest, then add a bit of real guitar, or sample someone elses if thats what ya want.
As for live... K'bds right paw keeps the numbers down. [Edit: Meant Left...]
So maybe a dying art like a harmonica or saxaphone player... might get to the 'Ohhh come and see this band, they have a real bass player!'