Voice is great but even with Android having a huge lead in this department, I still see people hacking away on their Google e-mails or texting rather than speak their messages. Here's the reason why. We have not been trained to use voice after decades of trusting the keyboard. And while iOS app, Apple's Siri, is pretty need, Apple needs not only build voice capabilities into the iOS but give us a reason to use it.
Take Ping on the other extreme. It's okay but we have no reason to use it. With the rumored voice capability that is forthcoming, I'm sure Apple will vastly improve on Siri. But will that be enough?
I've used Siri to look things up I've used it to look up definition of words. I've put Siri in the dock to force myself to use it. Practice using it so that I'm more comfortable with voice and when the time comes, I'll be able to take advantage of iOS 5's voice abilities. But that's me.
I'm sure you don't go to such extreme to use Siri or get yourself comfortable with voice input/output.
I have no expectation that the iOS update will allow me to chat with my iPhone the way folks on the Enterprise is able to make queries of the computer onboard the starship. However, I think Google will probably take us there sooner rather than later.
What I do expect is for Apple to attempt to make the use of Siri and other voice capabilities more second nature, and less of a conscious effort that I have to put in now to use it.
On another note, any other interest uses of the current Siri that you can think of?