Two reasons why I think it would make sense to do a new ST:
1) I would think that Ducati won't want to overlook the type of customer that doesn't want to need two street bikes to be able to enjoy performance handling in something that works on the highway. Not everyone wants a more narrowly focused track bike. Maybe their 2nd or 3rd bikes are off-road machines or bikes for other family members.
While I have no idea what the demographics and multi-ownership profile looks like when you get inside the industry numbers I do think a brand with Ducati's reputation for overall sport performance would look at the money invested in this segment recently by Kawasaki and Yamaha and ask themselves some hard questions. There has to be room for a lighter weight superior handling sport touring bike in the line.
2) Bike pricing and economics? Thinking back to my '03 ST4S that I still have in 2008 equivalent dollars it's gotta be close to $20k - at least $18k. Ducati has been leveraging new tech in the following few years successfully for a while now. You could say that was a key part of their marketing and manufacturing strategy that help them successfully reinvent themselves as a profitable, growing player.
$15K for a 1098? Why not $17-18k for an ST1098. Still leaves room for an "S" model under $20K. Would it be one of their highest volume models? Likely not, but I'm betting their incremental profits would be up there thereby bringing them a very nice ROI and expand their demographic reach.
