I am shooting the same thing as you are in my Wolverine with no intention to switch it to a 209 system. In my encore I have the .25 ACP because I don't want the heat of the 209's.
To answer your first question, I think we are along way from seeing the #11's and musket caps out of the picture, but definately most of the inlines made will probably have the 209 system.
To answer your second question, I believe we are seeing the ammo companies produce a product to fit where the inline industry is already at, that being 209's made specifically for inlines rather than shotgun shells. My guess is that they are doing research to produce 209 sized primers that produce the optimum amount of ignition for BP and the BP subsitutes.
Finally, I think there may be a musket nipple conversion for the Knight Wolverines, but I'm not sure. Mine shoots 777 loose and Dead Centers too well with the #11's to ever think of switching to anything else.
Smoky