You'll have to plug your phone into the computer to apply download the update. Once the update is available for download you'll get a notification on the phone telling you there is an update.
Sent from my Lumia 900 using Board Express
I got my phone on Friday after preordering. By Saturday the data started dropping and then it wouldnt do anything. Did a full reset and it started dropping again on Monday. Tuesday I spent hours on the phone with AT&T and they sent me to store for a new SIM. ATT store put the SIM in and it still didnt work. So, they gave me a brand new phone. When I got home Tuesday I saw the story break about getting 100 back and that you could have yours replaced now if you wanted. I thought to myself, so glad I went to store and already have a new one. Wednesday morning I woke up...........And the new phone has no data and cant send MMS.
So NO, the new phones probably dont have the new software, atleast mine didnt that i got yesterday.
They are probably delaying the next batch coming out until the software update is released considering most stores are out of stock. I'm waiting for my local corp store to get them back in stock so I can exchange mine with one that has a better camera button.