Thank you, Microsoft.
However, if you read it carefully, you will see that it says "We will use it for A and B. We won't use it for X and Y" and it doesn't say "We will use it for and only for A and B". This is why they need to mention that "we won't use it for X and Y".
Of course I haven't actually used or installed Windows 8!
Microsoft is known to lie and subvert their users, and I wouldn't trust anything with them.
I haven't forgotten about their smear campaigns and FUDs on Open/Free software, Halloween documents or their beloved manipulation tactics "embrace, extend and extinguish".