I hate to break it to you guys but outsourcing of mainline jobs has been happening for quite a while now in Europe. There is a British airline named GB Airways that flies A320s in British Airways paint and.... you guessed it, they are a "regional" airline.
If you want to see what's going to happen in the US for the foreseeable future, just look to Europe - tons of profitable LCCs flying "mainline equipment" (737s, A320s), profitable regional airlines flying "regional equipment" (which is to say, EMB 170s, 190s (eventually), yes, even A320s.) The only airlines losing money are the big legacy carriers still flying "legacy equipment" (widebodies, etc.)
Unfortunately, the domestic flying in a few years will be dominated by airlines like SWA, JBlue, Airtran, etc flying 737s 717s and A320s.... and also dominated by your Comairs, ASAs, CHQs etc. flying Emb170s, 190s, and eventually, Airbuses and probably Boeings. Why, because they are willing to do the flying for less than the mainline.
God help us all,
73