That app really makes my work with ATF easier and since I’m not the only to find it useful I’m posting it on code.google (FB 4.7):
http://code.google.com/p/atfresourcemanager/
Feel free to do whatever you want with it and maybe why not share back with everybody.

Side note: A few people asked me to implement the possibility to embed 2 format in the ATF (like only PVR and DXT for example) instead of just one or 3. This tutorial by esDot does mention it too:
http://treefortress.com/tutorial-compressed-textures-in-air-atf-format/
But so far I’ve been unable to make it work. Only the first format is embedded but the second one is ignored + the docs specify “or” which kinda seems to imply one only. Please share your discoveries on this.