We're used to Sony talking big. We wouldn't expect them to talk big about the PS3 just yet, considering its relatively dismal sales performance, but in comparing it to other consoles they obviously don't want to make themselves look bad. Interestingly, that led Dave Karraker, a spokesperson for Sony, to state that Nintendo's Wii is nothing more than an impulse buy. He also went on to say that there only “appears” to be more demand for the Wii because Nintendo isn't shipping as much. Nintendo, of course, disagrees:

"That's absolutely inaccurate," she said - claiming that Nintendo is shipping at least the same number of units as Sony. The NYT article also quotes "company officials" as stating that a million Wii consoles are being shipped around the globe each month, with the US receiving half of that number - and therefore more than the 100,000 PS3 units per month Sony has claimed to be shipping.
A million units a month? That would be an awful lot of impulse buying, if the figure is accurate. Regardless, to me it seems that Karraker is just trying to save a little bit of grace while Sony waits for the PS3 to pan out.