Nordstream will happen anyway. Southstream still has other unresolved issues beofre it happens. In the long run, we're all dead. John Maynard Keynes
To make more or less firm conclusions on what was the prevalent driver of the conflict (BTW, Yushenko secretariat just accused Tymoshenko of openly siding with Russia and aiming at political defeat of Yushenko... Russians say that negotiations were stopped in late December at Yushenko's direct order - the political/financial fight in Ukraine has been intense), we have to wait and see the parameters of the Russia-Ukraine contract.
What Russia has achieved, IMHO, is rationalization of the Russia-EU gas trade. Analysis and negotiations should become easier. Finland and Sweden won't be able to block or delay North Stream any longer. On the other hand, Europe now could rationally allow Slovakia and Bulgaria to restart their nuclear power plants, Germany would do the same, and in the long run Russia will be forced to rely on LNG more than it would have liked.
And finally, the grey trade should become harder with international monitors around. Purely on these grounds, non-transparent part of the trade must go down, which would help a lot.