you can find the deprecation plan here: http://downloads2.esri.com/support/TechArticles/W26496_W25918_DEPRECATION_PLAN_FOR_ARCGIS_101_and_102_FINAL_050713.pdf

REMARK: ArcGIS 10.2 will be the last for ArcSDE as an “application server”. This means companies/organizations using ArcSDE tehcnology as an application server, should start migrating to “Direct Connection” , which is a 2-tier architecture.