We don't know whether Sony will manage to make PSP last 10 years, but it's undeniable that an essential condition (necessary, not sufficient by any means) to have any chance to do it is to make it clear that they are willing to keep it alive so long, if it's possible. I they don't make this clear, obviously they lose developers and users support earlier. So the wider meaning of the statement is that if sales hold, they won't kill it early.
Edit: and obviously that they'll do their part also with SW support and marketing to try to make it last.







