I use Zite quite a bit and when I got my WP I was glad to see a WP version. I recently emailed them with a feature request and this is the response I got back,
I followed that up with asking him if there was a particular reason they were abandoning the WP version and his reply was,
Its a bummer we won't be seeing any more updates or work done on the WP version of Zite.
"Hi James,
Unfortunately we aren't going to be building out any more updates for WIndows Phone. We will be upgrading iOS and Android moving forward though. I invite you to join us on those platforms to get the latest and greatest features for Zite.
Thanks,
Trent"
I followed that up with asking him if there was a particular reason they were abandoning the WP version and his reply was,
"Hi James,
Zite is a small team and we don't have the resources to build out and maintain a WP app.
trent"
Its a bummer we won't be seeing any more updates or work done on the WP version of Zite.