There's no funding, or indication of if and when 407 would be constructed east of the existing. So hard to say. When the Ontario government started construction of the original 407 in the early 1990s there was no indication it would be toll ... until after the 1995 election, when the PCs were elected, and decided to accelerate construction and turn it into a toll highway. Whose to say what a future government will do to build an extension ... I'd be surprised if it wasn't toll though, but not necessarily the same owner and operator.
Oh here's
a press release I noticed, on the opening of the first phase of the Highway 7 expansion from 417 to Carleton Place; the current construction is the second phase, with the third phase to start in 2010.