Seeing that TfL is due to take over the North London (When is that due to
happen?), have they ever thought about further extending the DLR further
west?

Methinks that it would be a boon for Hackney, which suffers from a lack of
any tube stations.

I can imagine the DLR going out to Highbury & Islington, as it would allow
connections to the Victoria Line as well as to the ELL at Dalston Kingsland.
And NLL would terminate at Highbury & Islington.