RejZor, it is a firewall. Sygate free has no HIPS or IDS.
There is therefore no need to be worried that there is not coming any new version.
It is a basic packet filter disguised as an application based firewall. Has a few added features, but NONE that depend on updated knowledgebase like virus databases.
Many times especially new versions are maybe produced by commercial pressure to have updates, often causing various problems.
There is a tendency to adopt suite concept like latest kerio Comodo etc. are examples. They have their problems. Stability, memory usage ....
I am currently using kpf 2.1.5 and totally happy with it having my rules totally under my command.
As to Sygate 5.5, it is a good firewall for people not able to understand rule based firewalls. Keeps computer safe. I would not run other proxies though with Sygate except avast's ones.