You do realize that "believe in" implies a belief or faith of some sort? For your purposes, simply "what do you believe?" would be more accurate. Also, "believe in" would require something like "being the #1 selling console" not "will be".
Anyway, I really hope you're kidding about this. PS3 has used up more of its "arsenal" than both the Wii and 360 combined, xD.
“These are my principles; if you don’t like them, I have others.” – Groucho Marx