Yes, there are other music/mp3 shield out there, but SEEEDStudio does it again with a very complete unit!
The Music Shield is a professional audio encoder/decoder compatible with Arduino, Seeeduino, Seeeduino Mega and Arduino Mega. It is based on the VS1053B chip, which enabled it to play sound files from SD card and do short-time recording as well. You can also use it to play MIDI notes by slightly changing its hardware installations. Due to the SPI communication mode, it keeps a minimum number of IO port that facilitates users' own developments of this device. Additionally, the new multifunction button provides greater convenience for users to control.
Note: Recording is only supported on Seeeduino Mega and Arduino Mega for now. The maximum size SD card you can use is 2GB.
Please visit the wiki page for more info about this product. Feel free to help improve the documents, add more demo code or tutorials. For technical support, please post your questions to the Seeed forum.