"there is no point in writing an H.264 decoder for gstreamer since such a thing already exists and is in widespread use"
Unless you need a patent license, in which case you're going to want to use Fluendo's codec.
"Fluendo also offers an alternative H.264 decoder that hooks into gstreamer. In exchange for money they take away your freedom."
Umm, jein. Unlike FFmpeg, they *have* a patent license. So, you know, you don't get sued. With software patents, you're screwed either way. Pretty sure Fluendo *can't* ship a Free codec; it's almost certainly in the MPEG-LA license terms. I've asked the MPEG-LA to clarify their position towards Free and open source codecs for their FAQ; we'll see if anything comes of it. So, really, either way your freedom is gone.
Shipping known-patented code without a license is tasteless IMHO. Same as selling your friend stolen goods.