There are three major gaming markets, Japan, Europe, and North America. Other territories such as Australia have significant sales as well, but I rarely see numbers attributed to them (though recently Australia was mentioned as a strong territory for Sony).
Either way, the Wii is beating up on both Microsoft and Sony. It's continuing sales are remarkable. However, the Wii is a different animal to the 360/PS3, it's not really in the same race. Which may be why it's doing so well. Then again I'd put it up against the PS2 which is similar in capability and has 145 million units sold.
Returning to the PS3 and 360, aka the HD gaming market...
The PS3 launched anything from a year to 16 months later than the 360, yet it's already ahead of the 360 in terms of total units sold in both Europe and Japan. Worldwide monthly sales show the PS3 has a significant lead in terms of new units being sold, over the 360. Only in North America and to a lesser extend in the UK, does the Xbox 360 lead the way. Yet that position of 'leadership' is only a factor in two of the three major markets. Yes the US market for games is large, but so are Japan and Europe. Ultimately gaming is bigger than the US market, and with PS3 on course to eclipse the 360's worldwide sales possibly this year, but probably next, it's not likely that production will cease, nor is it likely that the Sony 'top brass' will do anything except sit and watch the cash flow across their books as the Playstation brand continues to be profitable.
One thing that is educational to do is to look at the total brand position. Look at Sony Playstation, that's PSP, PS2 and PS3 sales, plus all the games and accessories. Wii competes against both the PS2 and PS3, not simply the PS3. Wii is not an HD devices, so it's not in direct competition with the PS3. The PS2 is cheap and cheerful, but doesn't have the integrated motion capture the Wii has, but is otherwise similar in terms of capability. Wii competes against the Playstation brand , not just one console or the other. Nintendo DS and Sony PSP compete directly. Both are doing very well, the PSP has recently been outselling the DS in Japan, though the DS still leads elsewhere. In any event, both handhelds have healthy sales.
Sony was derided for continuing to sell the PS2, yet if you consider that the Wii is not an HD gaming device, it's a wise move to continue selling PS2s. Microsoft has only one device in the market, and it's an HD gaming device. When PS3 overtakes the 360 in global units sold, which it will, it's going to be very hard for Microsoft to continue talking up their success story when that success is likely to be confined to the US HD game market. In fact if you look at Playstation units sold (PS2 + PS3) Sony has been wiping the floor with Microsoft since Xbox 360 launched. Throw in the PSP and it looks even worse. When you consider Nintendo's total hardware sales against Sony's it looks far closer than it does if you consider only PS3 and Wii.
The trouble with most people and gaming journalists is that they have a very narrow focus. Widen the view, and the picture changes considerably.
Sony's big challenge is to catch the migration of users from their PS2s. Sales are beginning to decline for the PS2 now, it's time that they did something to move more PS3s into the hands of PS2 owners. A price cut would appear to be the best course of action.