A few things you should know about Mesa Airlines:
1. Mesa requires a training contract. I think it is a year.
2. They also have cancelled all vacations for their CRJ pilots for the last year. You will not be able to get any days off other than your bid schedule.
3. They have trips that will have a layover at an airport and not get you a hotel. It is legal because you won't exceed your maximum duty or flying time, but be bored as hell. Pilots sleep in the airplane until their next flight. You could walk through the terminal if you like but that doesn't sound like much fun either.
4. They give you a minimum of 8 days off in a 28 day period. You can assume that you will never get more than 2 days consecutive so it makes it extremely difficult to JS home and actually do something productive.
5. Delta Airlines has appealed the court decision last month and if the appeal overturns that last ruling, you can guarentee you will be furloughed. They will loose 20% of their profits overnight.
I know many pilots with low time that got on with them and moved on to a better company a year later. It worked for them and they were aware of the poor working conditions they were facing.
I am surprised they announced they were hiring when just last week I spoke to someone that was in their hiring pool. I am really curious what is going on over there. Be very cautious if you feel desperate enough to apply.