Intel is going to retire Atom S1200 and Z3700 series sooner than expected. In fact we have the concrete date for each series. The Atom Z3740, Z3740D, Z3770 and Z3770D will be discontinued after April 10 2015. The last shipment for the S1260, S1240 and S1220 will be done on October 9 2015.
Affected Atom CPUs
The Atom S1260, S1240 and S1220 are micro server processors while the Atom Z3740, Z3740D, Z3770 and Z3770D are ultra low power cheap processors for windows 8 and Android tablets. These Atom processors are based on silvermont architecture and manufactured using 22 nanometer manufacturing technology.
The upcoming Intel Atom Z37x5 series will be replacing Z37x0. The former has cores upgraded to stepping C0 and its embedded silvermont chips will be covered to D0.