I hope you guys with good jobs have really thought through what you'd be giving up. At 3 points in my life I had to take the decsion about trying to fly for a living or follow the route that would make me the most income. The first 2 times I passed on flying, but eventually got myself where I was looking at having the savings to retire at 50, owned a home, a truck, an airplane, a sportscar and 2 Harleys and had time to enjoy all of it. I had decided I would delay my goal of flying, then flight instruct to keep myself busy when I hit retirement. W'll that all changed when the dotcom bust killed the telco's. My company went bankrupt and I was laid off from my high paying management job. (I also had a lot of money stolen from me by the likes of Bernie Ebbers and a few other crooked CEO's of companies I'd invested in, but that's another story.) At that point, I again though about trying fly for a living and this time went for it even though I practically have one foot in the grave.
Anyway about a year later, I'm now a full time CFI making Ramen money at age 44. Even though I am still able to afford to keep the stuff I'd accumulated, not having time to enjoy much of it is a big downside of the job, as is wondering if you can stay on the flying career path and still achive other long term life goals. When you're used to living like a Captain at a major airline (income wise) it's tough to make it on $18/hour and getting stiffed after driving an hour to the airport for your one flight of the day.
I may or may not ever get a shot at an airline and at this point don't know if that's what I want, though it does seem like the shortest path to getting qualified enough for a good corporate gig. The 25 year old ATP rated CFI that just left my flight school to fly for a regional tells me he was the second youngest in his class and the oldest was 46, so that gives me some hope if I decide that's the path for me. At the current rate, I should have the mins for a regional by the end of the year if I can get enough twin time.
Anyway, I do know that were it not for careful management of the money I made before making the switch, plus the fact my wife makes a load of money doing a job she likes, there is no way in hell I'd be as happy as I am. My advice in the case at hand would be to keep the corporate gig, start working on collecting ratings at the local FBO. Then you should have all the ratings you need to start working as a CFI by your 10/07 start date and still not be in debt. From what I've seen only a small percentage of the folks that go through the "professional pilot programs" seem to get to an airline cockpit any faster than the guy who got his CFI at the local FBO. The rest end up with a boatload of debt working at the same wage as the FBO guy.
Folks thinking of making the switch really need to think through exactly how much they, and the folks that depend on them, will have to give up. My wife supports me 100% in making the change, but it still bothers me when I leave her with nothing to do when I work weekends and the times I have to tell her we can't do something because moneys too tight.
Good Luck and Choose wisely.