Reason at Fight Aging is not impressed by the recent Harvard news.
You might look back into the Fight Aging! archives for a primer on the intersection of telomeres, telomerase, and aging. It's interesting stuff, but unfortunately this present research is being headlined as "scientists reverse aging in mice" - which is absolutely not what was accomplished. Reversing an artificially created accelerating aging condition by removing its cause is not the same thing as intervening in normal aging, and it will rarely have any relevance to normal aging. The study results are teaching us something about the way in which telomerase works in mouse metabolism, but I - and other, more qualified folk - are dubious as to the relevance to human aging:
Even if it was reversing an artificially accelerated aging condition, has whole-body rejuvenation of this sort been demonstrated before? Not that I had heard of.