The geography of Russian oil production is changing rapidly: the West Siberian fields are being depleted, with most new production coming from East Siberia. There's an obvious geographic advantage in piping East Siberian oil to markets in East Asia. Of course more Russian oil going to East Asia means less going to Europe, and I'd expect Europe to make up for any reduction in Asian demand for ME oil. Given declining production in traditional American suppliers Mexico and Venezuela, the US is also likely to be a lasting market for ME oil

It is possible that a severe double-dip recession could drive another oil glut, which would have a major impact on the ME political stability equation, but it doesn't seem likely to me. Might want to take that one up with the "peak oil" enthusiasts, who see quite the opposite of a glut on the horizon!

Oil is an almost infinitely fungible commodity, with transport cost a minimal percentage of final landed cost. If, for example, Nigeria had a revolution tomorrow and stopped producing, Nigeria's customers would simply buy their oil elsewhere, albeit at a higher price. If hypothetical country x currently buys all their oil from Nigeria, they are not "dependent" per se on Nigeria for their oil, since they can just as easily buy elsewhere.

Many, probably most, oil producers, have security issues, and those issues concern all oil consumers, whether or not they buy from any given supplier. The US doesn't buy from Iran, but if Iran stops producing the US will be affected, because the people who do buy from Iran will be out bidding for oil from US suppliers, who like everyone else will sell to the highest bidder.

For me the pipeline is likely to cause some shifts in where different parties buy, but probably not to cause any major changes in the supply/demand equation.