Posted: 05/11/2015 at 16:00
If you scrape a little of the bark back with your thumbnail and it's green underneath then it's alive, or at least it stands a good chance of survival.
Have you got anywhere you can plant it in the ground? Salix = willow - they need plenty of moisture at their roots and ordinary potting compost just doesn't have enough body to hold enough moisture.
Otherwise I'd repot it in John Innes No 3 loam based compost and cross my fingers.