More blasts attempted in London BBC: London blasts cause chaos on Tube
CNN: Bombs a 'significant breakthrough'

They weren't quite able to pull it off this time, and hopefully this botched effort will lead investigators directly to the terrorists. I'd say that this lack of finesse indicates at least some desperation on the bombers' part. They wanted to keep us reeling, so they staged an attack they weren't prepared to carry out properly. Thankfully, this effort backfired, although as a terrorist action it was still effective. ("I am still shaking," says Sofiane Mohellebi.)