EyeToy sold around 10m on 130m PS2s for an attachment rate of about 8%, I think Sony should be pleased if their controller is anywhere close to successul as that. If PS3 went on to sell 60m a similar attachment rate to EyeToy would only result in about 5m "wands" being sold.
Microsoft talk about Natal as if it's the launch of a new console, I think their expectations seem way too high, I don't see it having a significantly larger attachment rate than EyeToy.
I'm sure Nintendo will continue with motion controllers next gen, but I expect Microsoft and Sony to continue with standard controller but probably with a motion controller as optional extra at launch.
As for continuing with their strategy of just more powerful systems, I don't see how that is related to motion controllers. Even Nintendo continued with the strategy of a more powerful system this gen.







