A few reasons. But looking at the whole spectrum of things, there are a few notables:
#1. The X360 is selling poorly in mainland Europe...Not the entirety of 'others'. This is due to a poor brandname image (MS is kind of the poster boy for evil American corporationism).
#2. The X360 in last place this Christmas might be bad to some, but is still beating what the Xbox did in the similar timeframe. The issue is that consumers are not picking the X360 over the PS3/Wii ultra-quickly. The PS3 has had the price drops quick enough to maintain the forward momentum the PS2 had, keeping it viable. The Wii is going off the ultra-casual momentum the DS has created and fostered in non-UK countries, scewing the data.
Despite this, there are still a few places the X360 is doing fairly well - a quick look at the console race shows the X360 is still maintaining some sort of decent sales in the UK, Scandanavia, Italy, Other Europe, Austrailia, and the 'others' markets.
The "issue" the X360 has is that it's doing quite well versus the Xbox, and will actually wind up the 4th most popular console in Other territories in history (next to the PS1-3, and Wii). But when you compare it to what the Wii/PS3 are doing, and the fact that the X360 is failing to totally stomp the sales patterns of the Xbox. The Xbox sold ~8m units in the "others". The X360 is already at 5m in 2 years. So it's done about 65% of the Xbox's LTD in 50% of the time.
Back from the dead, I'm afraid.
