Maybe, but the thing that made him lose in the first place, lack of support by an established party apparatus, makes him weak against the Muslim Brotherhood, which has a long history of organizing in Egypt. I doubt he beats Morsi in the second round. If he wins, the military will maybe overthrow him, but it depends on what he does. IF he follows his political views absolutely, then they will overthrow him. He'll need to compromise on his views about the United States and other regional powers if he wants to avoid a coup. Huge changes to Egypt's foreign policy. Much more belligerant to Israel, better realtions with Iran, the Saudis relationship with them will suffer. Turkish relations will imrpove, Palestinian relations will improve.
He won't be able to accomplish much economically but won't be as bad as the muslim brotherhood was. Some of his political reforms might go through, which would be good for Egyptian democracy.
Honestly, I don't think there isn't enough pan-Arabist sentiment left for his policies. He's running on a pure Nasserist platform, but hasn't changed it enough to be compatible with the modern Egyptian position domestically or internationally. His heart is in the right place, but if he starts making wrong moves, then he'll be overthrown in a military coup. His foreign policy is wishy-washy and will end up like Erdogan's "good neighbors" policy did, with all of Egypt's neighbors hating it. Egypt doesn't have the position of strength that it did during Nasser's era.
The military somewhat ironically understands Egyptian position the best but are a terrible government and damage democracy there, and are also corrupt. They do a good job at knowing proper foreign policy so foreign government's support them, but haven't enacted domestic reform well.