Louie Lorenzetti always insists that I go to this, or at least bring him one of the handouts. It gets a little depressing though; they always talk about the new versions of code that we don't have, and won't see for a long time to come.
John Hutchinson (Washington Systems Center) talked at length about the new features and gotchas in JES2 versions 4.
In version 4.1, you can provide lots of personal information on a //OUTPUT JCL statement, which later appears on the job separator page. Examples are your name, address, telephone and mail stop. The default page separator has changed a LOT and is practically unrecognizable from before.
Version 4.2 was released primarily for APPC/MVS support.
In 4.3 (available in March 1993) IBM has increased some of the old limits in JES2. Now you can have 9,999 RJE and NJE lines, and up to 9,999 initiators (imagine needing ten thousand initiators). The subsystem interface module HASPSSSM has been moved to CSA above-the-line.
Hutch also said a lot of effort is being put into 4.3 to clean up little irritants that have accumulated over the years. One example is the "JOB DELETED" message that SDSF displays in the job log before a job has even had a chance to execute. JES2 version 4.3 does away with that.