Usb 3

I'm looking to get an iMac next year. (Know the old advice of "buy one when you need it.") I don't need one now and definitely want to wait for Nehalem.

But what about USB 3? I suspect it will be impossible to add it to iMacs that don't have it, and it may be important for a computer that is to last 5 years.

Of course, USB 2 is good enough for just about everything, and there's FireWire for other things. But USB 3 may be enough of a standard to make it worth having. Within the computer's lifetime I may well want to import video from future HD cameras. Will USB 3 be required for that?

Also, any recent word on when USB 3 controllers will be ready? I was thinking early next year but not sure if that has changed.

I'm going on the assumption that the next iMac will have Nehalem + USB 2, and the following one will add USB 3. I can *probably* wait that long. Just looking for opinions on the advantages of doing so.

 

But would it take nVidia much longer to add it than it would take Intel? I figure that once it is released, most new computers should have it pretty quick.