Q: How do you close applications when multitasking?
A: (Scott Forstall) You don't have to. The user just uses things and doesn't ever have to worry about it.
A: (Steve Jobs) It's like we said on the iPad, if you see a stylus, they blew it. In multitasking, if you see a task manager... they blew it. Users shouldn't ever have to think about it. </p>

from the Q & A session after the recent iPhone OS 4 event, as reported by Engadget

So what's this, then?