An "edge case" though....?
This is all well and good, however both WSJ and FT are more "trade papers" than "news papers" IMO - the people reading them do so for commercial (i.e. employment) reasons. The news they gather from these sources, the effectively make money from in their jobs.
Also, the news on this type of publication may not be available elsewhere.
So, what you have is an audience consuming industry news, that they then use to inform their working decisions and that they may not be able to get from other sources.
None of these things apply to "general news" though - this can be read from any one of a number of sources - either electronic or paper-based.
I wonder too about electronic news subscriptions? Do many people subscribe to news papers anymore (as a total of readership)? Or do they pick and choose what titles they buy and when?
For example, I'll likely pick up a red-top for a commute as it's small, cheap and provides brain-out entertainment. But at the weekend, I'll pick up a broadsheet - expensive and much more in-depth. It's the distinction between news as entertainment (Metro) and to be better informed (The Times).
I'd not subscribe to either though as I buy papers quite rarely - and I suspect that to most people "subscription" equals "lack of free choice" - why shackle yourself financially to one provider when you can act on a whim at the news-stand?
Finally, when I'm done with my paper I can pass it on to a friend or colleague or leave a magazine on a train for others, or donate it to a doctor's surgery etc. None of these things will be possible on devices like iPads....