Yorba, a non-profit software group based in San Francisco which is behind Shotwell, the new open source photo organizer which I like very much, is putting together a multimedia creation suite (or something like that) for Gnome.
Miro is an open-source and cost-free application for watching Internet TV in high definition quality. It's available for Linux, Mac OS X and Windows.
Every major operating system has more than one media center solution for users who can't spend a day without watching a movie or listening to music. In Linux we're all familiar with MythTV and Freevo, two media center applications that are so appreciated they even have got their own distributions. Freevo is highly configurable, and Freevo 2 SNV builds look promising. MythTV has everything a personal video recorder needs, from scheduled recordings to weather plugins. The thing is, many people need a media center application just to watch Xvid files, listen to their favorite music, and watch family pictures on their television. If this is the case for you, give Entertainer a try.
You can manage most of today's multimedia applications easily with ReMoot, a universal remote control program. ReMoot even provides an esoteric way of controlling your PC remotely from your cell phone or PDA, earning it top geek points.
One of the less-touted changes for Ubuntu 7.10 is the merge of the Ubuntu Studio repositories into the main ones (hosted by Canonical). This means you'll be able to install entire categories of multimedia software (audio, video, graphics) with a single command (or via Synaptic, as usual). You don't care, right?
The non-free codecs distributed by Medibuntu now come to a single metapackage: non-free-codecs. The proper package matching the architecture will be installed (please see the Launchpad bug report below).
Amarok is a really nice music player that connects to Wikipedia automatically, supports lyrics, uses AudioScrobbler and MusicBrainz, and connects to your iPod like nobody's business.
MPlayer is a movie and animation player that supports a wide range of codecs and file formats. It also has a plugin for Firefox allowing you to view streaming video from your web browser. This short howto will help you get it up and running in no time.