What does this mean?

From what I understand, if you currently buy a "satellite ready" head unit, you can purchase a receiver for satellite radio, but you need to purchase from the same manufacturer of the head unit for it to function.

So is Nissan going to sell the satellite receiver? Or is the head unit from a specific company? Can you purchase either an XM or Sirius version of this?

Anyone know?

Thanks in advance

Nissan/Infinity is partnered with Sirius, so either there is a built in tuner, or you can purchase a sirius tuner and plug it into the the factory HU.

Have you checked out the Future Vehicles section of nissanusa.com? According to that, you can get XM or Sirus as a $400 option. Subject to change of course...
I'm getting Sirus when Howard Stern switches over, but will be getting a portible/cradle unit so I can play it at home or in car without extra monthly change for additional unit.