For widespread promotion of Windows 8, it was indeed important for Microsoft to expand their Windows Store network. Presently, Windows Store is available only in 5 countries. Though, this is not a big deal right now seeing it as just a consumer preview. But, it won’t be long when developers all across the globe would start developing Metro apps.
Probably, Microsoft is well aware of this fact and that is why they decided to launch Microsoft Store in 33 more countries. What this would do is fill the App Store with tons of apps just before Windows 8 is up for purchase. There are great chances of this interest for Windows 8 spilling over on to the Lumia Windows Phones.