Adobe Flash is an outright offense if you ask me. A distro providing a separate repo for non-free software is one thing, forcing me to run uninspectable code, which is known to have a horrible security record, under my user's privileges, is another thing. As OpenBSD people say, it's a feature that it's missing. :-P

I don't know what problem with media codecs there are. FFmpeg, as free software, implements H.264 just fine, even though it's a patented format. I don't know how exactly the legal aspects of that work, but I'm happy it somehow works, because otherwise I couldn't watch all my [spoiler]Chinese cartoons[/spoiler].

Now WiFi cards are a problem from what I know. You can buy a WiFi dongle with free software drivers though to get around that issue, or replace your laptop's WiFi card with one that has free drivers. I suspect that will be the one major issue with the GNU OS, and the only thing we can do is ask manufacturers of WiFi hardware to be more cooperative.

The other big problem tends to be the BIOS, but GRUB/Linux-libre at least boot just fine on proprietary BIOS, so it's no issue for those who don't care. Those who want to take the further step for software freedom may want to look into LibreBoot: http://www.libreboot.org/