The good old days will be 140 years ago, instead of just 60.
I know this is a somewhat off-the-cuff statement, but I think there's profound implications of this. With people living longer, our connection to historical events will become that much stronger. Growing up in the 70s and 80s, I view events from the depression era on very differently from events prior to that. WWII feels much more concrete to me than the Civil War because I've met and talked to so many survivors (both military and those that fled Germany) and heard so many personal stories. If Civil War veterans had lived to an average age of 150, I would have met some of them and see those events through a much different lens than I do now. If the founding fathers had lived to that age, there would a lot of us who could have heard first-hand accounts from great-great-great grandparents about personal encounters with those men...given how often we debate what their intent was when writing the constitution and creating our governments, it would make those discussions a lot more interesting.
It's fascinating to think about, for me, the implications of a world where events take that much longer to get put into the historical archive where they're no longer part of living memory. Would we, as a society, be more aware of our history and less likely to repeat past mistakes? Would people behave differently when the requirements for and results of leaving your mark on society change so radically? And would we spend a larger part of our lives studying what is currently known and delay entering our useful part of our lives or would we be just as quick to move from learning to doing?
On a less profound note, we'd need to come up with a better system for referring to ancestors. Having to say or write great-great-great so frequently would get annoying.