Microsoft have even produced a video, showing how it's done. In the video, four regular people (the Mom, the older lady, the Urban Outfitters cool-dude (casting brief: slightly hip and with-it, but not intimidatingly so, like those Mac-toting hipster douchebags) and, of course, the Token Black Guy*) stand around a Sony Vaio laptop in a regular American kitchen and discuss the activities you can do at a Windows 7 launch party. Awkwardness ensues. Yes, you too can have highly organised fun.
The whole video has that unmistaken sheen of ersatz authenticity so typical of a poorly-made astroturf campaign: the combination of shaky, pseudo-amateurish camerawork, professional editing and implausibly even lighting that suggests that the layers of Microsoft management who signed off on the campaign weren't sure of what they wanted: something that seemed "fresh" and "organic" but, at the same time, didn't let down the professional production standards one would expect from a Fortune 500 corporation campaign.
And here is The Register's impression of what a Windows 7 party, with a middle-class middle-English bent, would be like:
Now you'll have to excuse me for a moment while I do my hostess duties. If everyone can just come in here for a minute, and gather round the laptop, then we can begin. Yes, very funny Eric, you are allowed to bring in your drinks actually, so no it isn't at all like being at school again, and that was a silly thing to say. If you want to hear something funny, you should listen to what Verity says. Wooj, come on through and bring the others, will you?
* may not be available in all countries.