Jeez, dissapear for 6 months and your topics get locked!
As it would appear that the previous ITV thread has been locked down, it looks like we'll have no choice but to start afresh.
An updated version of this plugin is available via here. Github: https://github.com/ReallyFuzzy/ITV-Player.bundle
This uses the newest version of the Plex framework and, more importantly, leaves behind the ol'creaky Webkit Site Configs and moves to straight up RTMP streams. This a good thing as it should make the plugin available to servers on all platforms and more clients.
However, from reading about these forums it looks like this will still be broken for most clients out of the box as the latest free version of the PMS is broken when transcoding RTMP streams. If you're on 0.9.7.28 and not using the main desktop clients either downgrade to 0.9.7.22 or pony up for the latest Plex Pass version.
Edit (2013-08-01):
Updated version of the plugin (v.0.5) now available for manual updates via the link above. This adds more navigation options and search. The only thing left to do at this point is Live streams, which may or may not be do-able. Don't hold your breath waiting for those, unless if someone else kindly volunteers the code.
Additionally, the plugin will eventually (shortly?) end up in the UAS. Once it's in there, this will be the recommended way of installing the plugin.