This could be seen as good news. They have left the UK and will soon be shot or imprisoned.
The ones that survive will be back to recruit even more jihadis. The UK's human rights legislation has made anti-terror legislation close to useless. The high court regularly overturns any such laws as violations of human rights.
Last week the court ruled that all prisoners have the right to vote. A few years back, they ruled that non-citizens have the same -- or more -- rights as citizens, seriously impeding the ability of the government to hold suspected foreign terrorists for more than a few days without specific charges.
Zarqawu and his ilk know a safe haven when they see it.