Why Continue MP3 Development Given AAC? Options

[izscors]

Please don't take this the wrong way, but I am curious why there is continued development of MP3 encoding (such as LAME) when AAC is now long-known to yield superior quality for a given bit-rate (all other things being equal)?

I can sort of understand an explanation as being for the heck of it, but given that a superior method exists, why not work on improving even that instead? I'm not technolgically sophisticated enough to comment with any authority at all, so I pose the question.

[Engelsstaub]

Some here are saying that MP3 is "universal." I know of no devices that won't play AAC. My iPods play it. Android plays it. My daughter's Zune plays it. In fact the Zune (and Windows Phone 7) actually plays files purchased from my iTunes account which brings me to this point: if iTunes is the number one distributor/retailer of music (QT AAC @256 Kbps VBR,) how can one logically claim that MP3 is still more universal?

...the answer is it is still more universal for those who do their own encoding. (Probably.) Moreover Amazon, and some other retailers of digital music, sell it in the MP3 format. And yes: there probably are a few players out there that won't support AAC currently. Are any of these players of significant marketshare that the vast majority would have some problem playing back an AAC file purchased from iTunes?

An interesting side-note: every popular device I know of, for playing ripped videos (using Handbrake, etc.,) requires the audio to be mixed down in the AAC format. This includes the XBox 360, Playstation 3, and others. I would hate to have encoded my rips with MP3 audio and then try to find something other than VLC that will play it.

So in reply to the title of the OP's post, I would say development should and will continue because more than enough people want to use MP3 and see it developed to its full potential. These codecs can coexist and do so nicely. No one should be disparaged for preferring one over the other. Choice is good.

[Brand]

I know of no devices that won't play AAC.

I know plenty. Neither of my DVD players, which are 5-10 years old, play AAC. (One of them plays OGG Vorbis, tho, which is kinda interesting.)
My Nokia phone does play AAC, but not gaplessly. The program I use for playing music gaplessly on it doesn't support AAC.
Many PMPs I see don't play AAC, even new ones. For example the Phillips MP3 players and MP4 players only play MP3, WAV, WMA, FLAC, APE, according to the specs.

I don't have any hard numbers, but I'd say quite a significant number of devices currently in existence don't support AAC, but pretty much all of them support MP3. You have to take into account devices released some years ago as well, they are still relevant.
On sound quality.. I only did some limited testing myself.. while I think AAC does sound better at 128kbps (which makes it very attractive for some uses), I'm not sure there's an audible advantage over MP3 at 200kbps (or V2 bitrates), which is kinda the standard bitrate used for music nowadays.