And by that you mean? You will be using something else? Just curious...
SFGUI is already highly depending on OpenGL itself and there are only a 'few' things that keep SFGUI tied to SFML (so I've been told on IRC), so in future they may change those dependecies too and become a GUI library which doesn't depend on any other library directly, but don't worry they won't abandon SFML but rather restructur the rendering engine to be even more modular, so it could be possible to connect the GUI with other graphics libraries. (Although I think the modular renderer could take a bit more time than those 'few' changes, I'm not sure so you should wait for a official statement.)
But with changes ahead a fixed release could again get pushed further back.
Although I don't really see the big advantage of a stable release. Sure for distribution & updates it can be nice to have something that doesn't change anymore and for software security (i.e. that nothing crashes with a new version) it's also good, but I haven't seen a single SFML/SFGUI project that would heavily depend on any of those reasons and personally don't think that there will be on in the new few weeks/month.
The community and popularity has first to grow more, maybe this will happen largly with SFML 2, we'll see.