Well, let's not get ahead of ourselves here.
Talisman 4th edition revised was released in December 2008 followed a few weeks later by the reaper expansion.
The Dungeon expansion was released in May 2009.
The Frostmarch expansion was released in late October 2009
The highland expansion was released in mid May 2010
the Sacred pool was released in October 2010
The dragon expansion was released in September 2011
The blood moon was released in May 2012
The city expansion was released in January 2013
The Nether realms was released in December 2013
and The firelands was released recently in February 2014
That's a lot of expansion and when FFG is on track, they released an expansion for talisman every 6-7 months. When they are not on track, they released an expansion every year.
Currently, Relic was released in April 2013. We are getting an expansion March-April 2014. So, that's 1 release every 12 months. If they could keep that up for the next 2 or 3 years (ie a total of 4 expansions), I'd be thrilled.
I can imagine that the next expansion would be a small box expansion, to complement Nemesis, and I could see this coming out for Christmas 2014, but to be fair, FFG now has X-wing, Eldritch Horror and Descent second edition which probably take an awful lot of their time.
Although I don't really know, I can't imagine that FFG had so many popular games where gamers clamored for many expansion back in 2008-2009 when they released Talisman.
I sure would love to read about the list of releases through FFG history.