I'm not all that sure about the "PS3 will still have the best games," there's already reports and rumors about companies either wanting out of their contracts with sony to work on the Wii or them wanting to port their games over to 360. Hell, even the leader of the Gears of War team has said that he'd rather work on the Wii than PS3. While yes, people are still going to buy the PS3, there won't be enough. As a gaming company, which would you want to do: spend 20 mil making a game for 500,000 users, or spend 10 mil making a game for 4 million? This is the exact same situation in reverse that drove all of the companies to make games for Sony instead of Nintendo; so just saying they'll automatically have the best games automatically is pretty groundless.
Cost isn't the sole reason why I want a Wii over a PS3, although it's the main factor in which I buy first, the controller is the main reason why I want a Wii. Given how energized the game developers are about developing games to use the wiimote, I highly doubt that everyone will just lose interest in a few months. Given that the controller is the main feature of the console, it's hard to imagine that it will turn into "just another console." PS3's motion sensing is a gimick, the Wiimote is a marketing strategy; and given that I have yet to hear anything negative about the Wii at all(baring sony/xbox fanboys), it seems like a very effective one.
PS3 offers graphics, amazingly beautiful graphics, but that's all it offers. Games aren't a guarantee at this point other than the ones already announced, and a lot of those companies are talking about ports to 360. If the companies abandon the PS3, as past console wars have shown it happen, PS3's chances don't look good.
If the PS3 goes down in price, you won't see it for at least a year; by which time you'll be enjoying your 360 or Wii so much that you'll be even less likely to shell out hundreds more for another console to play mostly the same games. PS3's options for winning the market are running out fast.