It looks like it's possible...
I did a search for "dynamic pdf" on google and I found a site:
http://www.fastio.com/forms/form1040.html
that does it for the 1040 form. That just shows you it can be done. I don't think they tell you how because from what I've skimmed, they want you to buy their product. (That's how I interpreted the last paragraph on the bottom of the page.) From other stuff I skimmed it appears that you can use PHP 4.2 to generate dynamic PDFs also.
PHP and dynamic PDF:
http://www.devarticles.com/art/1/503/2
Good luck, and hope you can keep your job!