Like a lot of people, I listen to my music on the go on my phone. I don't have the ability to appreciate all this fancy new stuff.
The #1 thing Apple can do to improve my buying experience is to put lyrics in the USLT tags, so I don't have to hunt around the Internet or use some other tagging software.
The #2 thing Apple can do is offer songs in Apple Lossless. AAC was a good choice back when 128K was the bitrate of the day. But, in a world where everyone is selling 256K and 320K tracks, I'd rather get my music in a lossless format and convert down to VBR MP3.
I thought iTunesLP was a cool format. But, for the life of me I could never figure out why you couldn't get the full iTunesLP experience in on your iPad or even iPhone.