I suppose it might be possible (long shot) to set up the module to act as an Appletalk bridge by writing a custom firmware for it. / port something like NetaTalk / emulate an Localtalk node. Considering the CPU is probably going to be something like a Rabbit, PIC, or eZ80 with a few kilobytes of RAM and 32k-128k of Flash it's going to be really tight.)
WiFly:
* 32 bit CPU, 128kB RAM, 2MB ROM, 1MB (8Mb) Flash, firmware upload by FTP over WiFi or UART.
*
ECOS OS, TCP/IP, WPA2, DHCP, UDP, DNS, ARP, ICMP
Further thoughts: if you leave aside Appletalk access, and wish to connect the client to the net via any random WiFi network, could you skip the Netatalk part and have the module emulate a standard modem,
and the "dial-in" server? FTP could be used for Mac-to-Mac transfers. I don't understand all the TLAs included in the WiFly software stack, but is it any of it helpful?
eCos (embedded configurable operating system) is an open source, royalty-free, real-time operating system intended for embedded systems / It is designed to be customizable to precise application requirements / It is programmed in the C programming language, and has compatibility layers and APIs for POSIX and µITRON.
March 30, 2009 eCos 3.0 final release
/ incorporates many recent contributions to the public eCos project including:
/snip/
* PPP, SNTP client, VNC server, and enhanced HTTP server for FreeBSD TCP/IP stack
I note, with slightly off-topic interest, that eCos also runs on M68k/Coldfire and PPC }