This is an great board to experiment with ethernet. You’ll find more information on www.freertos.com. This includes an full light weight IP (lwIP) implementation and operating system.
The mane proplem with all these boards is the available TCP/IP applications. I’ve worked with the AT91SAM7X256 and my conclusion was that performance was sufficient for operating system and webserver, with some extra applications. Making it sufficient enough for hobby, but not really for industrial porpuse. If you really want more, a uClinux or embedded Linux sollution is much more logic. You’ll easily be able to choose from a hugh amount of applications, like tftp, web server, SLL, SSH, SNMP, etc. Making is suitable for storing music like on a MMC card. Leaving only the mp3 decoder. Eventhough not everybody will be able to choose for such a solution, this is the most rewarded one. Have fun.