What exactly do you want to advertise? Who is your intended audience? If you don't have a clear aim, your advertising isn't as effective.
It doesn't actually matter who your audience is if it's just telling people there's a product out there....just show the console doing it's thing (games, interface, multimedia), use some flashy CGI and whirly graphics along with a decent soundtrack and BOOM, immediately a million times better than nothing. Don't do anything other than show a Vita doing it's thing....later you can tailor adverts for specific groups but until those groups are aware there's a console it's too high risk to stereotype the console as "for group X"