Should I stay or should I go now...?

Over the past year or so I have had a few opportunities for career advancement. Some of which I've taken, others I've turned down for some reason or another. Today I was presented with a MAJOR (do you see that, it's in all CAPS, you know it's big) opportunity. This is the second time this door has opened for me, only this time it's big enough to drive a bus through. Simply put I'd be flat out stupid for not jumping at it. Then why you ask, am I even thinking about it? Well, you have to understand my situation. My current employer is such that, under normal circumstances, would take an act of God to get promoted for most people. However, my field is highly sought after and I'm only 1 of 2 people (the other is my boss) that possess the technical skill for what we do. Couple that with the fact that I bust my ass everyday and I'm very good at office politics and I've managed to turn myself into a "valuable employee". So I have been promoted twice in the three years I've been there. Mainly because I've been offered jobs with other companies and work has made a counter offer. Now this is where I could use some advice.

I very much enjoy my current job, my colleagues, and organization in general. One of the companies that has made me the previous offer has come back to me with what is basically the key to the city. What's the downfall you ask? Well, as of now I work a standard work week. If I accepted the offer, I'd be part of a consulting firm which means my workload moreless doubles. I'd be on the go all the time. Fortunately I wouldn't have to move.

Now here's where it gets interesting. This project that I would be potentially be overseeing has the possibility to expolde. (not literally) But let me just say that potentially the US Congress would be providing funding for it and you'd eventually see it on CNN. Yes. That kind of "big". Of course this is all a series of "ifs", but they're big "ifs". Still not seeing the downfall?

The downfall is that if I'm not successful, and/or the project fails, I am most likely out of a job. Another downfall is the fact that I am a standout at my current job, with the new firm, I'd just be one of many that have the same skill. Follow me?

Do I just need to suck it up and take a chance at the bigtime? I watch MTV Cribs all the time. I want to be on there! Doesn't everyone? The reality is that it's a big gamble and my luck usually sucks pretty bad...