The good news is that the cause of last month's launch failure has been found. The bad news...
That’s the immediate issue. However, this rocket failure is a bit more problematic. The flaw appears to have happened in the manufacturing process, and that’s the sticky point. If it were something procedural setting up for launch (tanking up the rocket, for example), that’s a relatively easy fix. If it were some malfunction in the machinery used to make the rocket (again, possible to find and fix in general), the flaw would’ve turned up more often. That leaves something that happened by accident, and that’s not terribly reassuring. How do you know when a problem like that is mitigated? What was the exact circumstance that led to the pipe being faulty?
Until the Russians can figure that out, implement a fix, and make sure that problem is eliminated — and that other similar mistakes are prevented — it’s too risky to allow astronauts to fly on board the rocket. And that, currently, is the only way to get humans up to the space station. The only other rocket currently capable of getting up there is the Space X Falcon 9, which has not yet proven its reliability, and in any case has not been cleared by NASA to carry humans (the Space X Dragon capsule could theoretically do that, but needs to pass a set of strict regulations to be (pardon the expression) street legal).
http://blogs.discovermagazine.com/badastronomy/2011/09/13/soyuz-rocket-flaw-found