The ten year plan is just marketing hype. The life of a console is determined by sales and game support. The PS3 is weak but getting better on the first, and strong but getting weaker on the second.

I don't feel like typing a wall of text about this, since belief in the ten year plan seems to come from the heart rather than the brain, but even the mighty PS2 being virtually dead after 7 years should settle things.

PS3 will only last 10 years if Sony keeps up the 1st party support and no more nintendo-like disruptions alter traditional gaming by then.

1. 2007 was 10.5m million SHIPPED by sony, not sold.

2. PS3 may technically be around for 10 years, however, if it is not the dominant console by the time the next gen starts, i.e. PS4 and others are released, it won't sell diddly squat for the last 3-4 years of its life.

3. Even if it did become dominant by some massive negative sales of the Wii, it would not sell anywhere near 10m in its last few years. As all sales trends are not flat. They are generally a bell with a long trailing tail. The length of that tail is specifically related to whether or not it was the dominant console.

Just look at PS2's estimated sales curve.
2000: 5.8m (*Basically only available in Japan)
2001: 16.4m
2002: 21m
2003: 18.7m
2004: 16m
2005: 17.6m
2006: 12.1m (All new consoles have been launched, obvious factor)
2007: 9.5m
2008: 3.4m through 7mos. Probably end around 6m.

As you can see, the PS2, the dominant console, peaked as all do in the 2nd/3rd year and then slowly declined until the next gen started. Then it dropped off much more significantly.

So far even Sony doesn't have the PS3 tracking 15m+ in any year, let alone the for 5 years straight. In order for the PS3 to have a 10m/year average (which is actually what I think you meant), it needs some much higher years to make up for the continued years after the next gen starts.

It peaked in years 3-4, assuming this is true for this gen, Xbox 360 will peak this year and next, then start declining. PS3 will peak next year.