Rickitek,
I just came off 5 months of playing the job search game...
Sometimes putting all your cards on the table is not a bad thing. What the person does with that information will definitely give you a feel for the person you are dealing with. Which could be a good thing if there your boss. If said person uses that information as leverage against you, you will know to run away before you take the job.
Its really hard to know, because everyone (Bosses and underlings) is a little different. The best interview I ever had was lost when during compensation negotiations because I was hoping the company would support my PE.
The interviewer said "WE DONT CARE ABOUT YOUR PE" with an almost angry tone.
What it comes down to is, would I want to work for a boss who seemed almost angry that I would even try to negotiate such a thing?
They could have just said "I am happy you have it, I will work with you on the PHD hours, but will not pay for it." Or any variation of that with a positive spin. Now that I got something else, I am glade I didn't get that job.
The most important thing is to get a feel for how your potential boss reacts to the information you give him. Interviews and Employment are two way streets.