I don't neccessarily know about that. 50-over cricket is repeatedly being described - erroneously, to date, but it might eventually come true - as a format which has seen its best days past.
Most people will not be familiar with 60-over cricket; it was only ever played in the ODI format in the 1975, 1979 and 1983 World Cups, and never aside from that. I'm not aware of it being played in domestic cricket anywhere, ever, except the Gillette\NatWest\C&G\FP Trophy in England (that's been 50 overs since 1999). Old non-WC ODIs in England did used to be 55 overs, but even that ended some time back now; the old eight-ball-over ODIs in Australia were 40-over matches.
However, most genuine cricket fans (ie, those who like four\five-day cricket) who have experienced both tend to agree that 60-over cricket > 50-over cricket. If the 50-over ODI truly does become an endangered species at some point, going for 60-over games (which were not possible on a large scale until fairly recently - last 15 years or so - without day\night facilities) would be a far better idea than anything else.
What ODI cricket needs is to become less like Twenty20. 60-over cricket would do just this; most other changes mooted have tended to be along the lines of "how can we make ODIs more like Twenty20", which is precisely the wrong way to be going about things.