From the Networker 7.3.2 Service Pack announcement:

• Support for Sun ZFS for improved support for customers running Solaris 10

We’re not actually endorsing ZFS you see
This is just to take care of our many loyal Solaris 10 customers.

I don’t care why they do it – it’s all good.

Zmanda: start your engines!
Thanks to James Dickens for spotting this.