From what I've read, they are encouraging people to upload their higher definition productions such as 24-bit, 192 kHz, .wav. It still may get compressed down but they seem to be indicating that because of our growing users of high-speed broadband services, compressed file formats are no longer necessary. Not sure if their system is still compressing it down however? It appears that's not necessarily always the case? There is an issue of compatibility with folks that utilize cheap little MP3 players that are still restricted to 16 bit, 44.1 kHz. So in that scenario, it still may behoove one to still dither down to 16 bit, 44.1 kHz? That would certainly afford you the highest compatibility across the planet. But if you want people to hear your completely pristine high resolution stuff, apparently, you can now do that with iTunes.

What's next?
Mx. Remy Ann David

Maybe they are planning for the future? In the future ... all will be lossless HD audio?

That's what the Apple website actually indicated John. Though it looks like their mastering tools are actually restricted to Macintosh users? So the rest of us PC nerds will just have to keep doing our Mastering the way we always have. They actually seemed to indicate that properly Mastered mixes will play at lower volume levels because they are already too loud? WTF? From their description, it sounds like there Mastering tools doesn't provide for a truly Mastered mix? It certainly doesn't seem like an audio professional wrote that? But instead, a program developer, number cruncher?

They're confusing me which is an easy thing to do at this stage.
Mx. Remy Ann David

Maybe its "mastering", not Mastering. Loudness plugin outsourced form another company and given the Macintosh candy-coating instead of $$$ gear and a room and a real engineer?

Basically what it does is gives you the AAC codec and measures peaks and inter-sample peaks before and after the codec while being able to listen to the before and after. The encode and decode will generate as much as 1.5db peaks so they give you a loop through plugin to monitor and listen so you can adjust your master while monitoring and listening to the end result. This is geared towards their iTunes Plus store to make sure that the codec isn't clipping the hell out of the masters that people are paying a premium for. Maybe it'll also stear people away from completely smashing the mixes.

I hope they can steer people away from brickwalling it.

Unfortunately, I believe there will be more stonewalling more of this coming year than brickwalling?

Us versus them.
Mx. Remy Ann David