PowerShell v4 support
In the new version, we'll support at least PowerShell 3.0. As for PowerShell 4.0, that's not confirmed yet. By the way, you can use the this workaround.
Mobile browser support for Web UIMobile browser support for Web UI
Yes, we'll pay special attention to how the Web interface looks and feels on mobile devices (both smartphones and tablets).
Email based approvals (click direct links in emails to approve\deny, ability to reply to emails to approve\deny)
We have that in our Product Backlog, and it is a popular request, but most probably it's not going to be added in the nearest version.
Support for log text entry fields in workflows i.e. inputing justifications\change release ID's etc as part of a workflowed task
We have a request in our Product Backlog to provide a reason for Approval Request and provide a reason why a request was approved. Probably, that's something you are looking for. This is not going to be a part of the nearest release, most probably, but it is a popular request. We'll keep it in mind.
Ability to manage Managed Service Accounts in 2008R2+ domains
Thanks for the suggestion. We'll think on that.
Can it functionally replace MS Identity Manager in the MS privileged account control framework
Could you explain this request in more detail?
Ability to revoke\'rollback' tasks and\or support for temporal changes (e.g. timed group membership changes)
We have some of that on our Product Backlog, in particular timed group membership, but it's not going to be a part of the nearest release.
(Better) support for multiple levels of approval (4-eyes)
What exactly do you mean by 'better'?