It has little to do with the software being free or not. libavcodec, x264… we have free software implementations of most codecs.
The problem is that these codecs are patented. If you don’t have a license for these patents (that cost money, do you want to pay for openSUSE?) it is illegal to distribute those codecs.
It isn’t a decision from the openSUSE Project, it is a legal obligation to not include the codecs.
Why others include those codecs then? Well… some of them are just not respecting the patents. That isn’t a problem until the patent holder sues you. If you are a little group of people without money… nobody is going to sue you to take a money you don’t have.
Others… well, Canonical Ltd. is a company from the Isle of Man - Wikipedia, the free encyclopedia… not part of the European Union, neither from the Commonwealth of Nations. I don’t pretend to understand its legal status…
So… openSUSE doesn’t includes patented codecs just because it can’t. If you want openSUSE to include them get the money to buy the patent licenses.
But note that the license will allow openSUSE to distribute the codecs… but probably wouldn’t allow its users to distribute them. So you would not be allowed to give a copy of openSUSE to a friend.
And before someone starts saying there are no softare patents in Europe… please read Software patent - Wikipedia, the free encyclopedia (and all related links).
About Flash. It is available in the “flash-player” package from the Non-OSS repository. From openSUSE 11.2 Firefox will come with an extension that will change the “download the plugin from Macromedia” to something that will suggests to install the package from the openSUSE repository.