Tim,
We generally make one large device, which is "reticule limited."
That has consistently been roughly the size you mention (~22 X ~24) for the last seven technologies.
Going larger is not supported by most fabs, unless it is a special process (with special equipment).
I once met someone from TRW, who told me they make imagers for the space program that are four times the X and Y dimensions of our largest die!
His yield was one die per run of 25 wafers (if he was lucky).
Of course, the imager sold for multi-hundreds of thousands of dollars.
There is a real question that we always ask: "is it worth making the biggest part?" It seems the answer to this is never very clear. Are we doing this for our egos? Or, are we doing this because it is making money? We never really know where the "sweet spots" will be, as with every technology generation we also face a new set of designs by the customers.
I am told that we are "caught up" with all 330 and 330T orders now. I hope my information matches that of our customers.
Austin