Not too sure how they're doing loadwise, I've heard mixed views that some flights go out nearly empty while others have a healthy number of pax. One thing I have heard from everyone that has taken them is that the experience is unparalleled; the offer good customer service, a nice new FREE lounge in Toronto, and the convenience of flying from downtown with shorter wait times.
And to answer your second question, they've announced that they'll be operating a new route YTZ
for the summer season. Most likely just an attempt to make due over the typically 'slower' summer season in terms of business travel, as flying from Toronto to Halifax on Porter would take an extra hour at least (although it could be convenient for pax from Ottawa and Montreal).