Has the price cut already been put into effect? Potentially, yes. One of our readers has let us know that he was able to get his hands on a 60GB PS3 for no more than $499.99 at a Target today. In our attempts to verify this we called the store he bought it from. They confirmed that the 60GB PS3 was, indeed, in the shop's system at the price of $499.99. Whether this is an error on the individual shop's part, with the price drop being put into effect early, we weren't sure.
We are currently in the process of calling more stores nationwide, to see how isolated this event really is. We will update this post as and when we get more information. If true, then this is an excellent start for what promises to be an excellent E3. Already Microsoft's keynote is overshadowed by Killzone 2. A pricedrop by Sony before the event even starts only adds to the pressure.
[UPDATE 1] A Kansas Target has the 60GB PS3 in its computer at $599
[UPDATE 2] Another tipster has told us that today they sold two at Circuit City at $499. Confused, the manager called it in and got a confirmation that it was correct. We are in the process of verifying this.
[UPDATE 3] A Target store in Rancho Cucamonga in California has confirmed that the 60GB PS3 is in their system for $499. It looks like there's no pattern to which stores are and aren't offering the price cut.
[Thanks Nathan and Alexander!]