Again the 360 would also follow similar pattern of price drops and big games.  Is great the ps3 has doubled in sales with the price drop but what if the 360 tripples with it's price drop then it is a mute point.  Looking at the month of august with madden and bioshock along with the price drop it would be interesting to see if the 360 can put wii like numbers.  Because of Bioshock along with blue dragon among others games and obviously Halo I predict the 360 outselling the wii in september.  Will be interesting to see the sales going forward.

"Again the 360 would also follow similar pattern of price drops and big games"

==> It is why I was mentionning special momentum
"PS3 price drop+big games without Xbox360 price drop (during the same month)"
If PS3 ooutsell Xbox360, It will not last for sure ...

I don't think it will pass the 360 in USA sales anytime soon myself. MS is getting ready for there releases that will let it have a good hold to the Christmas season.

In the US, the PS3 should stay reasonably close to the 360 during the holidays - there are finally enough HDTVs out there to justify getting BluRay, $500 is just barely affordable, and there enough games to justify getting a system. (Sony doesn't need to worry about outselling the 360, because they have the PS2 to tide them over.)

The crossover point will be when the price drops to $399 - somewhere between March 2008 and July 2008. It's going to be the perfect storm - the US audience expands from 10 million potential consumers to 100 million, BluRay takes off, and the first great PS3 games hit.

Gamecube and Xbox had plenty of months in the USA where they switched off almost monthly for second place, especially in 2003.  The race for 2nd place worldwide is always pretty nasty, in the USA I think we've reached a point this generation where even a 3rd place console can sell 15 million units (more than Xbox or Gamecube).

If Metal Gear Solid 4, GTA IV, and a PS3 pricedrop come within the same month, PS3 should beat 360 rather easily.  Say the three occured in March 2008, I think you'd see PS3 go from 25k-40k/week to 45k-70k per week for about a month.

Alot depends on 360 releases too -  Banjo is going to be a big game for Microsoft next year, and Too Human could be pretty big as well, so I'd say alot depends on timing.

Remember there is also unreal 3 and haze which would debut in 2008 for the 360 which I assume based on later releases of 360 to ps3 games had more features etc. Increasingly more games are finding their way to 2008 such as today alone in the dark though they are multi platform because of installed base they will sell more on the 360 or worse yet for the ps3 they could be delayed for the ps3 for what has now become fairly common time exclusives. I really think there will be alot of really good games for the 360 in 2008 but MS just hasn't felt the need to talk about them and focus on the games coming out soon. Many analyst predicted that the Wii or 360 would be a distant third or that basically one of the systems would be a distant third this gen which looking at the numbers it is turning out to be the ps3. Obviously analysis have been wrong many many times but if there is a distant third the ps3 has the best chance with the current numbers to be it. 

The 360 has a huge cost advantage over the PS3, and it's not because of its age. In that respect, there is little reason that the 360 should ever really be priced higher than the PS3 unless it can somehow command a higher price on the market and maintain good sales.

Of course, maintaining good sales alone is hard enough for MS at this point. They're advertising the 360 as 'starting at $279.99' and many gamers won't even really know the difference between that and the premium.