Correct, SRT Blubyu...the poly is a distinct cross-breed stage between a wedge head and hemi head design. It allows for some offset in the valve orientation, but driven by a standard valve-actuation of a wedge head design. The Gen 3 has nothing to do with that, in the same sense that a Gen 2 has nothing to do with that.
The Gen 3 Hemi shares the valve actuation concept of the Gen 2 Hemi (though not down to the millimeter in physicality, of course). More or less, canted-valves oriented across from each other and actuated using 2 rocker arms as pivot points (one for intake and one for exhaust). Both valves intersect perfectly on an "imaginary" spherical geometry/surface (which does not necessarily correspond to the actual surface of the cylinder head...that's where people get really tangled up on what this is all about). It is that natural orientation of the valves on this surface, combined with the physical spherical surface (whether in whole or part) inside the cylinder head that makes it flow so well...it is essentially bespoken by Nature, herself, the way it all lines up. Of course, it is going to flow good.
I was just going to post in to note that it is good to see many responses here recognizing the updated distinctions that make something qualify as a Hemi. :thumbsup:
My answer was going to be...this is topic has been discussed ad nauseum in the past, and the best answer that can be offered is that they are all
marklar. 
Someone above already astutely noted that not even the Gen 2 Hemi (i.e., the legendary 426 from decades past) qualifies as a "true Hemi" under prevailing purist definitions, hence the attempt to make any meaningful distinction that separates the Gen 2 vs Gen 3 is largely moot. Either they both are good enough to be considered Hemi's, or they are both just "trying" to be Hemi's and missing the boat. So the easy answer to it is that they are both good enough to be under the Hemi brand name, and let's be done with it.

They are both a distinctly different type of animal from the more common wedge head design. If they were just wedge designs, Dodge could just have called them Magnums, and been done with it.
On the subject of an actual Poly design, I think Dodge does have one in one of their other smaller/older v8's (or is it a v6?). It's some sort of "new-world" sohc engine in the 4.7 L range? Help me out here, guys? The interesting thing about that is that it is in a very unique position to "transition" to become a "sohc Hemi" design, if the designers ever wanted to go that direction. It's already got the ohc in place, and all it really needs is valves arranged in a canted position with finger followers to the cam, and viola!...sohc Hemi.

It would be a smaller engine on this stage, but it also would be positioned to take a 2-valve/cyl Hemi design into the world of high rpm. Update for aluminum block, vvt, Multi-Air, modern emissions/mpg, and that could be an interesting development, imo...