There's certainly something weird going on here, either the pin counts are not we've been lead to believe or they've been using revised sockets for sometime as just mentioned (doesn't look like it from the Asus photos on their site), or someones going to get egg on their face.
If BD does fit straight into an old AM3 socket and works with a bios update, then frankly i'll be disappointed. We want a cpu that ushers in a new era for AMD, not one that rehashes the past, having backwards compatiblity with AM3 cpus is one thing, but this makes BD look like a rehash of Phenom, nothing wrong with Phenom, but we want something new.
Furthermore, if Asus's support for BD in their current boards is anything like their support for my board when Thuban was released (it was on a select list of supporting boards like this one http://event.asus.com/2011/mb/AM3_PLUS_Ready/
) then BD will not work very well in them. It took four bios revisions to get the multipliers reading correctly, and even today, nearly a year later, fsb overclocking is almost impossible, you're lucky if you can reach 215Mhz on my board, whilst with the 940 I had before it would do 280Mhz.