If the opportunity with the new company is that good, you might want to invest in an American Express Platinum card.

That way you will at least be able to retain some status, but I wouldn't do it immediately, as you still have a couple years for you to drop to the status that the Amex will give you. Check the site for details.

I wouldn't reject a good job offer because of FF benefits.

Just remember, now that you have to use miles/points to get your flights, sometimes, as it is with Delta, a SkySaver first class can be cheaper than a SkyChoice coach, so, not all hope is lost