Last year, Paho migrated from the Eclipse Git / Gerrit / Bugzilla infrastructure to GitHub. With this there has been an increase in issues (bugs) being raised as well as an increase in code contributions in the form of Pull Requests. At the time of writing, the Paho components have been starred 1766 times in total and users have forked the code 967 times.
There are currently more than 780 closed issues and 217 unresolved for released Paho components. Issue, PR and mailing list activity has consistentl external contributions and interest. The number of committers has increased by 3 over the year, and the number of code authors is at least 50.
As of November 2016, the last month I could find metrics for, Paho still has the second highest website traffic of any Eclipse IoT project behind Mosquitto. This means that the MQTT projects have over 50% of all Eclipse IoT measured website traffic. Paho had the highest measured downloads of any Eclipse IoT project in November 2016 with over 20,000 in that month. This statistic omits many downloads of Paho which can be obtained in other ways (external package repositories or source, for instance).
These figures show continuing increase in activity and interest around Paho and MQTT year on year. They are only a rough guide, but show that there is consistent interest in MQTT and Paho.
We are collaborating with the mbed (mbed.org) community on embedded MQTT clients: http://mbed.org/teams/mqtt/ The master source resides in the Paho project.