Sony has only done well with the Playstation, the thing they had with the Playstation 2 that was the best was of course, the game selection, because of this it didn't need to fight the Xbox's and Gamecube's hardware, the only thing it originally had to fight hardware-wise was Sega's last console, the Dreamcast.
I don't think Sony had planned this happening, Dreamcast dying off and two more consoles coming in about a year or so after its inital release and thus because of it being out longer, was able to have a larger game library, not only that but let's face it:
SCEA made great games(Sony's weapon for when times got rough), many game series started/continued out on the Playstation 2(Which usually implies the company will stick with the console, which was what happened, Devil May Cry, Metal Gear Solid, etc.) and the Playstation 2's controller was alot better than the other consoles' controllers and the Playstation 2's price point was great(Added many people already had a Playstation 2, so whats the point of buying a completely new system when you can just keep adding on to the one you have?)
I think Microsoft saw what happened to the Playstation 2 and I believe thats why they decided to release their console early, alot of the 360's fuckups were actually pretty small but were exploited a huge amount, they probably could have prevented this by releasing it later on but they saw their opportunity. Sony's plan for the Playstation 3 what I think was basically this(They probably planned this exact same thing out for the Playstation 2, but due to the events that happened, they ended up coming out on top):
Make the hardware top-notch, while of course this should be one of the top priorities on your list, you shouldn't have to have it so powerful that the price goes up(The hardware to me seems about the same as the 360's hardware, so why there's an extra $200 on the console is far beyond me, perhaps the 6-axis controller gimmick?), make the console itself look good-looking(By this I mean, it feels like it's a rich person's console, perhaps this was intentional so people would feel like the extra $200 would be worth it) and by just getting a bunch of really good looking flashy mediocre games together(Of course, there's also the games that will be "console-only" for the system so hard-core fans of series like Metal Gear Solid will have to get a Playstation 3).
Basically, the Playstation is all look and I have a feeling thats all it ever will be.
As for the Wii, I think the Wii is going down the same path as the Gamecube, all those 3rd-party games that were supposed to be amazing ended up being terrible or mediocre, while the 1st party games are great and the whole idea of how the gameplay works is a great idea, the game selection just isn't enough.