Microsoft's recent price cut for the 360 seems to be having exactly the effect they wanted. According to a recent statement from Redmond, sales of the console have skyrocketed in recent days. Sales increases of over 100% have been noted, and in some special cases as high as six times the normal sales rate.
The price cut represents a big change in how the console is perceived in terms of dollars, as the cheapest 360 is now below the cost of a Wii. Will the increase in sales carry on long enough for Microsoft to actually regain a lead, though? Probably not - the existing base of 360 owners is already pretty large, and at this point it would be more Microsoft taking customers from Sony or Nintendo.
I would like to see more specific numbers for Japan, since that is one of the regions they have struggled the most in, but they did not mention anything based on region.