I'm not sure when the plans appeared--to me it doesn't matter. What matters is getting debt free. My wife and I owe enough and I will likely earn little enough (by physician standards), and her little enough, that we could easily drag payments on for 25 years. But I think that's a terrible plan. If you have the means to do so, pay off those loans as quick as possible. Why let your loan balance balloon over 25 years? (You mention 20, but I believe with the exception of PAYE, all income based plans require 25 years of payments for anyone with any graduate loans)
I get very worried when people ask about how to just minimize their IBR payment and max out on IBR/PAYE/etc forgiveness. If your husband makes enough that between the two of you, you could repay the loans much sooner, they why wouldn't you do that? Pay off those loans ASAP--starting now! You may not have the loans yet if you're still pre-pharm, but think preventative. Borrow less than the full cost of tuition if your husband is working. In fact, if he's working you probably shouldn't need to borrow anything for living expenses, and hopefully you can pay cash for some of the tuition (don't forget all the education tax credits--that's not unsubstantial at all).
I can't tell you how much I wish I worked more at preventing my loans from being larger now. I didn't live extravagantly in medical school at all, but I still feel like a little financial education/planning could've gone a long way. Being young, poor, and a student goes hand-in-hand and is actually kind of fun (as long as you have basic needs met). Being older, married, with kids, and significant educational debt, while trying to save for retirement, college, pay a mortgage, etc., is not fun.
In my mind, PSLF is the only forgiveness worth planning for (since it's tax-free, and not in the far distance future(. And even, you better have a contingency plan because I can guarantee you that program will change. The big question is whether it gets changed for current borrowers and/or people making PSLF-eligible payments.