This is somewhat the first thing that I've done with ESP8266 in a state that's worth looking at.
I've started developing for esp8266 by adding limited support for it to antares (See experimental branch), which is my tool of choice for MCU development. Next, I've started developing alternative firwmware for those modules, since stock AT commands pretty much suck. You can grab the current code in it's crappy state at my github repo here, there are some binaries under binary/ directory.
So far I've got an u-boot like commandline running on the device with proper commandline editing, history and code completion (Pretty much thanks to the awesome microrl library) which can be easily extended with new commands and configured using menuconfig.
Antares blackblade 0.2-rc1, Insane Mushroom @ ESP8266.
(c) Andrew 'Necromant' Andrianov 2014 <email@example.com>
data : 0x3ffe8000 ~ 0x3ffe8a68, len: 2664
rodata: 0x3ffe8a70 ~ 0x3ffe9ab0, len: 4160
bss : 0x3ffe9ab0 ~ 0x3fff0ef8, len: 29768
heap : 0x3fff0ef8 ~ 0x3fffc000, len: 45320
=== Press enter to activate this console ===
blackblade > help
help - Show this message
iwmode - Get/set wireless mode. Available modes: NONE, STA, AP, APSTA
iwscan - Scan for available stations
blackblade > iwmode
Wireless mode: AP
blackblade > iwmode STA
Wireless mode change: AP -> STA
blackblade > iwscan
BSSID bc:ee:7b:35:bf:d8 channel 6 rssi -83 auth 3 tishina70
BSSID 24:a4:3c:46:ae:49 channel 6 rssi -90 auth 0 ubnt
BSSID a8:15:4d:c:be:c channel 11 rssi -43 auth 3 frostgate