We are making few lines of sets simultaneously and we don't want to spread their delivery for years. Inevitably, we have to give priority to these lines, even with out 30+ sets/year.
Having said that, there will be other ancient and medieval sets in the not so distant future. No further details at this stage though.
With that comment; I've noticed that these things seem to run in cycles. For a few years there seemed a drought of Napoleonics as other eras were being produced by the several main companies. For awhile it was WWI; Strelets produced an extensive Crimean War range. We see "Colonial Conflicts" being addressed by several companies and for the last year or two Nappies have flooded to the point it's difficult to keep up with all the great sets.
What SR has just told us confirms that in my mind. The Ancient cycle is coming - hopefully I (who reluctantly had to limit my range of collecting) will get the break I need to catch up on my painting all these great sets that have come out.