Given the growing concern about Hamas/Hezbollah/MuslimBrotherood/ISIS/etc. in the region a democratically elected Fatah regime could conceivably garner significant support from places like Egypt, Jordan, Qatar, etc., but getting to that point seems unlikely.
As for the 'unity' government, it's a bit hard (and, perhaps, disingenuous) to dismiss Abbas because he represents only the West Bank and then dismiss Abbas when he tries to remedy that situation. Had Netanyahu not sabotaged the talks, there is every reason to believe that Hamas would have worked ceaselessly to sabotage the very 'unity' government that Netanyahu disparages.