I'm curious what your thoughts on this are...
Precursor: MP3 works fine on everything AFAIK. All soundtrack files I have will be made available in their original format for direct download on the soundtrack pages regardless of what follows here. Currently, the best experience with the HTML5 Playlists is only on Firefox and Chrome, as MP3 and OGG are both supported natively in those browsers.
So here goes...
I've been trying to figure out the best solution to present the digital soundtracks pages. There's really no perfect solution that encompasses the major desktop browsers (IE, Firefox, Chrome) AND mobile platforms (Android/iPhone) simultaneously.
The primary issue centers around what the different browsers support in their HTML5 audio players.
They all support MP3 AFAIK, which begs the question, should I transcode the OGG audio into MP3, only for the streaming players/playlists? I think this would give the most bug-free experience on all platforms for the streaming player.
There is also the WEBM/WEBA format, which can convert TO/FROM OGG losslessly. This is supported in all browsers, though IE and Safari require a third-party codec plugin for DirectShow and QuickTime respectively. It is also supported on Android, but not iPhone.
The only issue I've been having with trying to transcode to WEBM/WEBA, is that the files are not seekable in IE, Firefox. Additionally the playlist function in wordpress does not seem to like them. It show's a download link, instead of playing them. Which leads me back to MP3, or abandoning "universal" streaming player/playlist.
Bear in mind, the direct downloads do load and play just fine natively on Android. I do not believe iPhone supports OGG playback in this way.
My goal is/was to have both an instantly playable/streamable player for the soundtracks as well as provide the full direct download links. I want to get to a place, where we have the nice full site, direct download links for all the soundtracks, but also a jukebox that will work from say your mobile phone. So you can always have some great adventure game soundtracks even when you are on the go and forgot to download them beforehand! I do this all the time haha!

Anyway, those are some of my current random thoughts...
~Andrew