I honestly doubt this model would come to fruition. Sony has two financial concerns the first is that each console they sell is profitable. The second is that they cover the astronomical debt they have incurred. They need to catch their breath and make some money. Otherwise you are not going to see PS4. The rotting global economy isn't going to be doing Sony any favors. High end electronics and entertainment are especially susceptible to economic woes.
Microsoft is actually in a more tenable position to reduce their MSRP. They have been in production longer. They have retained their original price point longer. They have generated greater licensing revenue. The result is that they can effectively dig deeper then Sony at the point. Sony realistically needs another year to reach the cost production advantages that Microsoft is enjoying right now.
You have to be realistic Sony wants to make money rather then get involved in a protracted price war. Microsoft wants to make money rather then get involved in a protracted price war. Neither company wants to put themselves that far out of position against Nintendo financially.
Sony did two massive price drops last year not out of a sense of competition they did so to save their struggling console from oblivion. That was most definitely not their plan. They took a more massive loss doing that remember that MSRP drop actually increased the losses off the original production runs that were produced at a much larger cost. These rapid price reductions are not the norm. They are extreme exceptions. We shouldn't be thinking they will be common place.
Nobody wants the war. However it is hard to imagine Microsoft being as vested as it is not retaliating in the extreme. Were Sony to go at the three hundred dollar point be the end of this year. Microsoft would go to two hundred or less. All Sony would accomplish is to push the 360 into the low end market where the majority of console sales are made. That is where non core gamers start to invest in hardware in a big way. Microsoft would not only increase their sales from that price, but they would drain off sales from the PS2.
You probably shouldn't hold your breath waiting for massive price cuts. I expect Microsoft will get around to a fifty dollar cut in North America some time in the coming months, but that will probably be it for the cuts this year. That would place Sony and Microsoft at parity for the cuts.