Quote:
Previous iterations of this document laid out a roadmap for exploratory virtual machine and language innovations from Adobe to be pursued via a rearchitected Flash Player (referred to as Flash Player "Next" and ActionScript "Next"). However, by its nature, this type of architectural innovation is disruptive and generally not backwards-compatible. As Adobe has learned in the past from transitions between generations of virtual machines (from ActionScript 2 to ActionScript 3), this places a high burden on developers who want to take advantage of features and APIs which may only be available via the new runtime, or which may require significant porting of content, frameworks, and libraries. Given this, as well as the growing importance of browser-based virtual machines, Adobe will focus its future Flash Player development on top of the existing Flash Player architecture and virtual machine, and not on a completely new virtual machine and architecture (Flash Player "Next") as was previously planned. At the same time, Adobe plans to continue its next-generation virtual machine and language work as part of the larger web community doing such work on web-based virtual machines.
TL;DR there are going to be no significant improvements neither in language nor in virtual machine.