Take this job and shove it

I work for a doctor at a big hospital. Big whoop. I have been approached about working also for another doc who has just been made staff after finishing his training here. I know him and he is great, very nice and hysterically funny. Also hot, but that doesn't matter. Just saying.

Anywho, it would be for about a year that I would work for him, and my current doc. When his clinical practice is up and running full swing, he would get an assistant who would only work for him. I know I can handle the work load, and like I said he would be really nice to work for, but it sounds like they don't want to give me a pay increase for taking on this additional responsibility. I have a meeting at 2:15 with my boss to go over the details. I thought that I would ask for a 50% increase and hopefully end up with around 40%. I know damn well they are going to say that I will get a better raise NEXT YEAR if I do this (they have hinted at this).

Now, am I out of line in thinking that I should get the money now? What if I leave this hospital - no money. What if I am hit by a truck - no money. WHAT IF. I believe the raise should occur immediately. They could always reduce it when this assignment is over. What do you guys think?