Per Apple, 10.6.6 includes the Mac App Store - http://support.apple.com/kb/HT4459
Quote from the link:
The Mac OS X v10.6.6 Update is recommended for all users running Mac OS X Snow Leopard and includes the Mac App Store, the best way to discover and buy new apps for your Mac.
Yes, that is what the KB article says I noted, but I definitely agree with wj that you need to go to 10.6.8. I was only pointing to the DVD version of SL you get when you buy from the Apple phone line, and while that is what hte KB artilce says you need, you should upgrade to the top of the line form of Snow Leopard, 10.6.8. You need that version should you want to move up to Lion or Mountain Lion.
wjosten and I are NOT in disagreement on this point. Buy 10.6 from Apple then use the on-line software upgrade to download the 10.6.8 Combo and ungrade to 10.6.8.
Hope this clarifies this point.