The same way the PS1 and PS2 did (if I'm understanding the question correctly).
It should be "Here's a game machine (it also plays movies but that's a bonus)" instead of "Here's a new movie machine, we have a couple of games coming out for it too!".
What earth shattering game did the PS2 come out with then? I bought the PS2 close to release and there wasn't an even remotely worthwhile game on it for a long time. I think mine came with Ridge Racer (which sucked). Gran Turismo 3 only came out a year later.
I'm not even referring to specific games at this point. I'm just looking at what is my impression of Sony's direction with their gaming division that, as a consumer of their goods, I find slightly dissatisfying.
Yeah, the PS2 had a crappy launch lineup as did the PS1 (well, actually the PS1 was a little better). But when the PS2 was released, it had a low, UNIFORM price point and it was designed as a game machine with almost 90% backwards compatibility with its former library. True, it was purchased as a primary DVD player by many in Japan, but it was technology that was a few years old and already fast working towards an affordable price here in the states.
The PS3, on the other hand, launched at $200 ~ $300 more than it's previous two consoles because they wanted Blu-Ray in there. Sure, those discs can hold 50GB which is mighty impressive, but you'll have a hard time convincing me that half that space isn't going to waste. Actually what I envision is 5 extra hours of cut-scenes that somehow ties together the little bits and pieces of action where you're actually controlling what's on screen. Of course, its nice that you get to watch Blu-Ray movies on it, but, as someone who was originally planning on getting a PS3 (before the initial price announcement), it would have been nice to have a choice between next-generation games OR next-generation DVD's. I still have an old TV and I'm not repurchasing my DVD collection, so Blu-Ray is pointless for me right now. But if I want a PS3, too bad for me, I still have to essentially pay for a player I may not use anytime soon.
Meanwhile, the PSP has been out for over 3 years and I still feel that everyone who mentions the system talks only about the movie watching capabilities. I hardly ever hear actual games discussed*. Yeah, there's more than a enough decent games for the system and I've managed to find a couple that I enjoy, but I've turned mine into a NES emulator/portable movie player.
(* Of course
this thread pops-up and throws my comment in the crapper.

)
Sony's not all that foolish. There's more moneymaking potential with a movie format than with games. I'd bet anything that they'd throw their entire Playstation brand off a steep cliff to establish Blu-Ray as the ONLY option for purchasing discs.