The Palestinians Arabs who fled Israel in 1948 were "traded" for Jews from Arab countries who fled in 1948. The numbers were roughly equal with about 100,000 more Jews. Since this trade has already taken place. Furthermore, usually population swaps in nationalist conflict are done to make the respective countries more ethnically homogenous and prevent further conflict. Hania's plan does the opposite and would be likely to encourage more violence. The obvious population swap in this situation would be to draw a national border that includes Jews living east of the 1967 line in Israel and includes Arabs living west of the line in Palestine. This will minimize nationalist friction.
UN: Gaza could be 'uninhabitable' by 2020 if trends continue (AP)
from the article: Peace Plan: Trading settler Israelis for refugee Palestinians