My feeling is that the NDP surge will be more muted than people are expecting, this time around at least. They'll probably win 10-15 seats in Edmonton, along with Lethbridge-West and possibly Calgary-Fort, which will bring them to official opposition status. The next election (in 2019, most likely) will be one to watch, as the presence of a strong, progressive official opposition may cause the progressive vote to coalesce around the NDP.
Furthermore, for the NDP to break through in places like Calgary, it will probably take more than a single election. Remember, the NDP's citywide popular vote in Calgary was less than 5% in Calgary in 2012.
I agree with this assessment.