This may be too late, but what the hey.
Never resign from a job just because you suspect you are about to be fired. By resigning you may forfeit valuable benefits. I repeat: Do not resign for this and many other reasons. Seek legal guidance to avoid acting incorrectly or irrationally.
–Steven Mitchell Sack, “Getting Fired,” Warner Books
You should consult an employment lawyer. You shouldn’t sign a piece of paper that you yourself admit misrepresents your intentions.
And this is where we learn the definition of the idiom “keep your eyes open” and the word “may”, children.
Thanks for all the offered advice. I was gone and getting married in the meantime…
Anyway, all the stress was for nothing… they kept “extending” my last day by a week at a time. Now I’m supposedly here until the end.
Guess I do good work. shrugs
Anyone looking for a System Admin/Web Programmer/Build Engineer? 
Can’t say my loyalty has been hardened by this ordeal.
Congratulations all around, Superfly. Keep at that job search and you’ll find the right thing.