As a PC enthusiast (love building high-end PCs but prefer playing on consoles) the thought of a 2013/2014 GPU using DDR3 baffles me, personally i think this is worse than any other crap Microsoft is trying to pull off.
I think that you are making two big mistakes here: first, you comparing these consoles to a PC when, despite what Sony and Microsoft may want you to believe, are still pretty far off what a high-end PC is. Let me remind you that the PS4 is using not a GPU, but an APU. Completely different rules apply to it when you don't have to deal with the CPU-Mobo-GPU interface and have both CPU and GPU on the same die (I don't know if Microsoft is using a dedicated GPU or an APU on their console, though). Second, you are giving this way, way too much thought. GDDR3 is not that uncommon in PC GPUs. Heck, basically the low-to-mid tier of GeForce 600 Series GPUs (and the vast majority of the 600M series) is still using GDDR3. And since the Xbox One and PS4 are on par with a mid-to-high-ish tier GPU, I guess it won't be a deal-breaker.
Remember when developers had to somehow code for the PS3's Cell and split RAM? And yet, they managed to provide games that were, basically, the same as their 360 counterparts. This is by no means the worst crap Microsoft is trying to pull off, because, in the end, it will make very little difference. You can't just look at the number after "GDDR" and assume that one shits all over the other. We know next to nothing about the Xbox One's graphic processing capabilities, so everything right now is pure (tiresome) speculation. Let third parties ship multiplatform games and then we'll see who outperforms who. But, right now, don't sweat it, man.
Also, PC MASTER RACE :P
They are both using AMD APUs, Memory bandwidth is a huge factor when you are building an APU based system (i've build some), even though it is a low-end system it is smart to add high speed DDR3 (2400mhz) to get extra graphics performance from the chip, while when you are building an i5/i7(high-end system with discrete graphics) a mere 1600mhz ram would suffice.
The biggest difference for this Gen is that both consoles will be x86, no more Cell crap to get in the way of multiplatform development, that means the ports will be virtually identical and you'll witness the performance gap much like you would if you were to swap a 650 to a 670 on your gaming PC(not saying that the graphics performance of Xbox One and PS4 are equivalent to those cards, it is just an example).