HS sold around 800 K so far i believe so I doubt it was a waste. Also, I suspect the investment for the engine will carry forward into new games in the same way it does for Insomniac so I doubt they're burning money.
I like HS but it was too short, also without giving too much away I thought it finished well and closed of its main character... so I'd rather I new IP that builds on the engine/good points of HS while avoiding the bad.
And those shots do look like a new IP...
Try to be reasonable... its easier than you think...