From the Swordpoint page on the Gripping Beast web site:
"After this initial schedule, we will be concentrating on producing campaign supplements which go into more detail about the refighting of great campaigns and wars of history (think, for example, of the Punic wars or the Successor wars, or the campaigns of Charlemagne). We are looking for enthusiasts who are interested in collaborating with us in the development of these further works."
And on the "Publication Schedule" thread in this discussion forum, Martin said:
"These books will include extra army lists, extended and tailored army lists, and either a series of scenarios or a campaign. All Swordpoint lists are and always will be compatible with each other. As an example, the Charlemagne book will include 8 scenarios, new lists for Old Saxons and Gascons/Basques (The Vascones) plus extended or tailored lists for Franks, Slavs, Avars, Lombards and Byzantines. There may be more once we can set the print length- we will be working to keep the price as low as we can without sacrificing quality."
"Experience is the teacher of all things."
~ Gaius Julius Caesar