People under the stairs just released a new album called Highlighting using a new codec called HD-AAC (also known as MPEG-4 SLS) that was created by Fraunhofer.
Basically it's a file that contains both a lossy AAC version and a lossless "HD-AAC" version but in about the same file size as an all lossless ALAC file. So it can be played by any software/hardware that plays AAC, but the lossless part can only be played by an HD-AAC decoder.
According to the video from Thes One and some comments by someone that worked on the production on this page: http://pl70.net/highlighter-hd-aac the files should be playable in lossless by iTunes and newer iPods/iPhones. However, I'm 99% sure they are misunderstanding the format and only the lossy version is playing. iTunes identifies the songs as 192kbps AAC files and makes no mention of HD-AAC. Also I can't find a single spec sheet or piece of information online that says that they (or any software/hardware for that matter) actually support anything more than the AAC core.
Also, I found this video of a Fraunhofer representative that explicitly states that iPods don't support the lossless portion of the audio (skip to 3:57 in):
Can anyone point me to a piece of software that can be used to play or convert the lossless portion of HD-AAC audio?