Yes, 4.2.6p5 from 2011/12/24 is still "Production" release,
and 4.2.7p445 from 2014/06/12 is marked "Development" release:
[ http://www.ntp.org/downloads.html ]
But only since 4.2.7p26,
upstream has addressed the problem of NTP being abused for dDoS,
and as of today, there are still 2121 NTP Server
which are vulnerable to mask and multiply attacs by factor of 700 (!)
(latest scan of NSFocus Security).
Thus I urgently vote to take 4.2.7p445 and followers into the tree,
at least as "~" :
we don't need that potentially threatening reputation, do we?
#533076 is the bump bug for 4.2.8