Let's Talk About the Al-Mahdi:

[Aquila]

I found this on a website addressing Sunnis:

Sunni Documentation on Imam al-Mahdi (AS)

For the Sunni brothers, there are six major collections of traditions based on the Sunni standards for verifying the authenticity of a tradition. These six books are: Sahih al-Bukhari, Sahih Muslim, Sahih al-Tirmidhi, Sunan Ibn Majah, Sunan Abu Dawud, and Sahih al-Nisa'i. I just quote few traditions from these six books to prove that a knowledgeable Sunni brother/sister can NOT deny that:

al-Mahdi (AS) will come in the last days to make a universal Government,
al-Mahdi (AS) is from the Ahlul-Bayt of the Prophet (PBUH&HF),
al-Mahdi (AS) is from the progeny of Fatimah (AS), the daughter of the Prophet (PBUH&HF),
al-Mahdi (AS) is different than Prophet Jesus (the Messiah),
Prophet Jesus (AS) will come as one of the followers of Imam al-Mahdi and will pray behind him in congressional prayer.

http://www.al-islam.org/encyclopedia/chapter2/2.html

It would appear that many Sunni do believe in the coming al-Mahdi.