Those would actually be a better approach than hacking a WiFi router, this way the sensor system could be compatible with any wireless access point....
And with the TCP/IP file stacks that Microchip offers for free, it should make it easy to implement this system, the OP could even run an SNMP Agent and even make each sensor DHCP enabled.... these are all pretty easy to implement using Microchips file stacks and libraries, I had done something similar but using the ENC28J60 Standalone Ethernet controller...