Yes, but you havw to consider that in 2008 the NDP had an extremely weak candidate in Toronto Centre and put no resources whatsoever into the campaign there (the same was true in 2011 but a rising tide raises all ships). The proposed new TC is extremly fertile NDP territory in terms of the makeup of the riding and you can be sure that in 2015 the NDP will run a high profile candidate there and put maximum money into the campign.
And let's remember, too, that the 2008 and 2011 campaigns were hampered by *who* the Liberal incumbent was, i.e. to run an overly-aggressive NDP campaign vs the former NDP Premier ran the risk of coming off as quixotic sour grapes that's more of a voter turn-off than turn-on. So, better to let Rae relatively off the hook and concentrate elsewhere.
Of course, next time it'll likely be an open/non-Rae seat, which'll make things easier.