There is no set release schedule for Showkase and unfortunately, I do not know when the next version will be released or what new features might be included in it.
Showkase is always updated shortly after a new version of Juicebox or SimpleViewer is released to include the latest versions of the image viewers and we aim to fix all known bugs and will release a new version if we deem a bugfix to be important.
Please see the Version History for a historical record of Showkase releases. This is not really a guide as to when the next version might be released but it might give you an idea as to the rough timescale between versions.
If you would like to be notified of new releases, please join our mailing list at the foot of the Showkase home page.
There has not yet been a public beta version of Showkase but if we have a private beta version anytime in the future (which we have had in the past), I will certainly keep you in mind.
Thank you for your interest.