Publishing work in areas you're no longer interested in
It depends.

Some questions might help guide you to an answer:


how important is the work you've done ? If it's not yet publishable does this mean it's not complete yet ? 
Since you're not in the area, do you even know if the topic/solutions are still relevant ? 
Are you proud of this work, to the point where you'd be annoyed if someone else came up with the same ideas and published them ? 
How much effort will it take to make the work publishable, and how does this interfere with current work that you're doing ? I.e are you in the initial stages of a Ph.D and can spend time on this, or are you deep into your own research where the context switching might prove distracting ?