Sanyo has finally revealed that the name of their PTT replacement to the Sanyo 4900 will be named the Sanyo SCP-7200 after all (though Sprint may push forward with another name, similar to how they called the Samsung A620 the VGA1000).
Earlier today (as they have done in the past), Sanyo accidentally leaked details of the phone on their web site, only to pull them later. You can see the details of the 7200 still (they kept the page up, but pulled the links), at the address below:
http://www.sanyo.com/wireless/handsets/scp-7200.htm