But will sailfish ultimately being successful , allow for N9 to see a whole new set of apps? if not , will sailfish apps be easily converted to harmattan?
I personally don't think so. In fact, it's not really helped thus far. What it has helped though, would be stuff like the Nexus 4, 2012 version of the Nexus 7 and potential Android devices that it will support.
The N9 is basically more ignore than even the N900.