If confirmed, this is great news

From the BBC:

The leader of al-Qaeda in Iraq, Abu Ayyub al-Masri, has been arrested, according to media reports quoting the country's defence ministry.

Masri, also known as Abu Hamza al-Muhajir, was detained in the northern city of Mosul, reports said.

The US military in Iraq said it was currently looking into the reports.

The Egyptian-born militant took over the leadership of the group from Abu Musab al-Zarqawi shortly after he was killed in a US air strike in June 2006.

Al-Qaeda in Iraq has been blamed for or has claimed responsibility for some of the bloodiest insurgent attacks in Iraq since the US-led invasion in 2003.

And unfortunately, this may not be correct:

A US military spokesman in Baghdad said he could not confirm that Masri had been arrested, but did not believe the reports to be true.

But let's hope it is as the BBC points out this is what this guy was all about:

Masri is believed to have helped Zarqawi form the first al-Qaeda cell in Baghdad.

After becoming leader, he vowed to "continue what Sheikh Abu Musab began" and avenge his death with attacks that would "turn your children's hair white".