According to the recent update from Microsoft, they has made the decision not to deliver any further full version releases of Forefront UAG. This news has posted in Microsoft's Official Server & Cloud Blog.
As per the update from Microsoft,
Microsoft customers continue to have access to select remote access and secure application publishing capabilities through Windows Server 2012 R2. Windows Server is not a complete replacement for all UAG scenarios, but it does provide:
Customers will be granted a Windows Server 2012 Standard server license for each UAG server license with active Software Assurance to allow them to make the transition. For customers who wish to continue using Forefront UAG, Microsoft will provide maintenance and support through the standard Microsoft support lifecycle. Mainstream support will continue through April 14, 2015, and extended support will continue through April 14, 2020. Customers with active Software Assurance on UAG as of Dec. 1, 2013 may also add new UAG server instances, users, and devices without any requirement to order additional licenses.
Please See Important Changes to the Forefront Product Line for complete notification.