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.