Below are the links to the IBM pages that list the end of life/end of support dates for Gentran, Sterling B2B Integrator and Sterling File Gateway. I was unable to get the specific pages for DataStage, Transformation Extender, Sterling Connect:Direct, Sterling Control Center, and Sterling Secure Proxy, but there is a software lifecycle search portal that allows you to enter the product name and it will list all the versions with their end of support date, which I have linked to below.
Brooke wrote a post a few years back called "Leaving A Legacy" that addresses the benefits of staying current and Brad wrote one called "Staying Current and Supporting Systems With Overlapping Functionality, Issues That Often Confront IT Decision Makers" that addresses the dangers of not staying current.
We are working on getting this information for OpenText/GXS/Inovis, Cleo/EXTOL, and TIE Kinetix, and I'll pass it on when we get it.
Gentran Products
https://www-304.ibm.com/
Sterling B2B Integrator and Sterling File Gateway Products
http://www-01.ibm.com/support/
DataStage, Transformation Extender, and Managed File Transfer Products
http://www-01.ibm.com/software/support/lifecycle/index_w.html
