I don't think it will be able to pass the 360 until 2011 (and ultimately, I'm far from sure that the PS3 will ever pass the 360).
In 2008 and 2009, MS will be able to start tapping the $200-250 consumers while Sony will still be $300+. That alone will postpone any huge gains by Sony until they can really get into that price region in 2010 or so.
And between now and then, a million different scenarios could arise to drastically change that one way or the other so it's really useless to speculate.
Anyway, to answer the OP: No, the PS3 cannot and will not pass the 360 in WW sales in 2008. Chances are also seriously stacked against it happening in 2009.
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