5 - Snapshots (Cannot be done with Phonon)
7 - Channel subscriptions
12 Displays video metadata. Could be somewhat linked with related videos...
14 - Subtitles, see http://google2srt.sourceforge.net/
17 - Search for playlists http://code.google.com/apis/youtube/2.0/developers_guide_protocol.html#Searching_for_Playlists
18 - Safe search levels (in the status bar beside the video definition option)
19 - Show more thumbs on hover with animated crossfade
20 - Accept any URL and scrape web pages searching for YouTube videos.
23 - Restore status when a recent keyword is clicked: skipped videos, sortBar and play time
24 - Add menu entries for Most relevant, Most recent, Most viewed (Playlist => ...)
28 - Phonon::MediaSource does not work with QIODevices (this needs to work to implement seeking)