That's debatable. As I recall during the last election they said "subways but only after we balance the budget", and their budget proposals included tax cuts. So yes, they weren't against a subway proposal but they also weren't in favour of paying for it during their term; funding a subway was one of the lowest priority promises.
So, what's Brown's policy? We don't really know as there's no detail on the ordering of the budgets. The question is, will he maintain a deficit budget to fund infrastructure (of any kind) and implement tax adjustments (or massive overhaul of hydro) at the same time.
Also, tax cuts reduces debt the province can take on, so even if infrastructure payments are years away that borrowing space may simply not be there. Happened to Toronto (Gardiner max'd out debt room) and buses needed to be purchased using capital-from-current out of a fare increase.
Thus far Brown's primary voting base wants Hydro addressed and some kind of tax decrease. Infrastructure spending mostly isn't there. The question is just how flexible does he need to be to get 905 votes.