I would like to know what the original plan was. I seem to remember reading way, way back when the show started, that they (Rachel and Aline) had mapped out the four seasons. They knew it would be four seasons (and hoped the CW would give them four seasons), because they had it all outlined.
I want to know how Greg would have fit into the four seasons. Because there's no way they knew from the pilot that Santino Fontana wouldn't want to do a TV series for more than one season (I read that somewhere recently; and that his wife is in NYC, etc.). They had to have been surprised. Right?
Pure speculation: I can see that if Greg had been there for the entire four seasons, they would have had the typical rom-com love-hate situation. And then he would have been endgame, right? The snarky guy right in front of her the whole time!
All this being said, I want her to end up with none of them. She and NuGreg can be buddies, Josh is her past, Nathaniel is a dream guy...but none of them works as endgame, IMO.