In what circumstances are people's names shortened and given an '-ers' ending?
Is it seldom heard? It's still quite common in our circles, although it is deliberately reminiscent of our school days' method of speaking. The problem with the idiomatic use of language is that it's related to a non-fixed sub-set of people.
The language and slang used when talking to school friends is usually very different to that used when talking to family members.
To answer your question, that kind of language is used extensively in IT departments across Bristol, UK. Specifically, the ones I work in.