As Jon Stokes over at Arstechnica describes, it would appear that AMD has changed its tune when it comes to the way Fusion technology will be implemented.  Bulldozer, as we originally thought, was going to be a completely new CPU design from the ground up.  But now AMD appears to be backing off that plan and going with existing CPU and GPU designs for their first Fusion product.

But in a financial analyst day meeting early this past December, AMD revealed that the company’s first Fusion product would “use existing CPU core and GPU core technologies,” suggesting that Bulldozer had gotten the boot in favor of a core from AMD’s current lineup.

In a recent InfoWorld interview, AMD confirmed that Fusion will be a dual-core design based on the Phenom core in its initial incarnation. There’s still no word on the GPU that AMD will pair with Phenom as the second core on the die, but apparently something will be announced relatively soon.

So now that we know that Fusion will combine a Phenom core with an as-yet unannounced GPU core, we can put together the following picture of AMD’s mobile “Shrike” platform, due out in the second half of 2009.