I doubt that will happen, but hey, 10 years is a long time, perhaps they might change their mind. So far, nothing done related to these passport changes and requirements has been retroactive. For visa waiver countries there are clear guidelines about when the requirement for mechanical readable and electronic passports started. I doubt they will come back 4 or 5 years later and say all those passports which are not electronic are not valid anymore. For example, green cards have been left to live their full useful 10 years life, even as newer more secure cards were issued the older ones were not automatically invalidated. One could argue this leaves a 10 year security issue, but that's life. I think it is better this way, just to incrementally replace these documents instead of forcing everyone to replace their documents at once.
On the other hand, what is the rush to get a new passport that although can look nicer and might seem to provide a smoother passport control experience could potentially subject you to tracking, skimming and eavesdropping. With an ePassport you'll always have to wonder whether your personal information is secure or not. I know, I know, they are supposed to be secure, same way as the DVD encryption protection was supposed to be fairly good, and we know what happens today. I would see a more likely possibility of an ePassport to be "recalled" over security issues that a regular passport having to be replaced because any country stops accepting them.
I don't know why they insisted in making the passport contactless, as one always gives the passport to the immigration officer and they could easily introduce it into a reading machine that would read it by contact. For me, this is a technology that is not going to do much for security and can just make the unsuspecting regular folk more trackable. Add this to other ways of tracking, like credit card payments, having your cell phone on, security cameras. I know, I know, people say if one has nothing to hide then it has nothing to worry. Well, say that to the Jews in Nazi Germany, or to the Tutsi in Rwanda, or to any other group that from a peaceful situation go into being persecuted and killed. Would you like someone, or the government to know you so well then when the winds change against you? Personally I prefer my freedom with as much privacy and anonymity as possible.
My 2 cents.