In the long-term it has to be seen as a good thing, presuming it holds, but there are a few caveats, not least of which is the (relatively) short-term impact of an aging populace on a dimished working-age population - automation will presumably mitigate that at least somewhat.
It is likely to see retirement ages and the like rise further, although with improved healthcare that's not necessarily an horrendous state of affairs, although I can see the subjective feel that people are working longer than they should being a very real complaint.
What's going to be the biggest impact, I think, is that the geographic spread of this is going to see a massive shift in relative productivity, military strength and the like towards Africa which will continue to grow as other regions stabilise or shrink; as China and India are currently the dynamic, low-cost, labour-rich economies undercutting the established nations, so Africa will take that mantle over.
That said, the world population was estimated to be around 1.5-1.7 billion in 1900, and over 6 billion in 2000, and that's with the impact of Spanish Flu and two world wars thrown into the mix - we've handled massive population changes before, and it's likely we'll manage this lesser one as well.
O.