.. finally made the switch and flashed OpenWrt to a TP-Link WR703N router, added a 16G memory flash stick, and connected to my first F5529 LaunchPad. Here is a picture of the setup.
The version of OpenWrt is 12.09. To connect with the MSP Launchpad, need to install the acm driver by
opkg install kmod-usb-acm
And also installed "screen" for serial client by
opkg install screen
Apart from the missing bridge library that come with the Yun, i'm quite satisfied with this setup, especailly the tiny form factor of the whole package.
The LaunchPad seems to enjoy running with her new Internet companion!