The September 11th fee definitely was going to (more or less) double (the more or less is because it depends on whether it's a one-leg flight or a multi-leg flight as to whether it's doubling or not), though I don't offhand remember when that goes into effect.
That was part of the year-end buget agreement reached in Congress.
I hadn't heard about any other fees/taxes doubling, though. You'd think that if that bill had doubled lots of fees/taxes, it would have been all over the news the way the (more or less) doubling of the September 11th fee was.
But obvously, if they increased the passenger count (that counts for taxes/fees) from 1 to 2, that could very well explain it. (But you'd think they'd be able to tell you that!)