Thanks to CD Freaks we've learned that Nero has released a FREE AAC encoder. In a nutshell, the Nero Digital Audio Reference MPEG-4 & 3GPP Audio Encoder will take your .WAV files and encode them using the MP4 format.
    Nero Digital Audio Reference Quality MPEG-4 & 3GPP Audio Codec
  • Compression Ratios ranging from ultra high (58 CDs fit on one!) to High-End Audio (2.5:1), for absolutely perfect audiophile encodings
  • Crystal Clear, Award Winning Sound Quality at every compression ratio and bit rate!
  • Support for Embedded Album Art (Covers, Booklets, Lyrics!)
  • Store Entire Audio Album in a Single .mp4 File with all the Features of an Audio CD embedded inside, but at a fraction of the space!
  • Reference Quality MPEG-4 Audio Codec
  • Fully Compatible with the Latest Version of the State-of-the-art MPEG-4 Audio Standard (LC-AAC, HE-AAC and HE-AAC v2)
If you'd like to check it out, the Nero Digital Audio Reference MPEG-4 & 3GPP Audio Encoder can be downloaded here.