Is this an official site?

I thought at first it was made by fans but infact it seems to be made by MSN. Nice site.

I'm not 100% sure, it does look official... it was revealed last year:
blogoscoped.com/archive/2005-0 ...

Yes, it is. Some WHOIS database results:

whois.sc/msnsearchspoof.com

Registrant:
MICROSOFT CORPORATION
   1 Microsoft way
   Redmond, WA 98052
   US

Technical Contact:
   Hostmaster, MSN
...
etc.