I think people have done a decent enough job of explaining how fantastic having 6 cores with hyperthreading is for 3D modeling and rendering (as well as video encoding), and also how those extra cores and hyperthreading do absolutely nothing for gaming. I think I saw them mention how the quad-channel memory architecture of Sandy Bridge-E (and in the future, Ivy Bridge-E) will give you twice the memory bandwidth of Sandy Bridge, Ivy Bridge, and yes, Haswell (Adobe products benefit greatly from this, as does anything else that hogs memory... Virtualization anyone?).
Rather than debating the specs, I'd just like to say that I love my i7-3930K. I love the Asus P9X79 Deluxe motherboard that I stuffed it in. I'm also very fond of the 32GB (4 x 8GB DIMMs) of 1866MHz DDR3 memory that I topped the system off with. Having loads of very fast memory has made my Adobe software collection very happy. I also get unbelievable performance out of the virtual machines that I boot up on my system. I have a Windows 7 Home Premium VM that has a WEI score of 7.2. As a matter of fact, I can boot up 3 VMs and it feels like I have 4 computers running that are all better than my previous gaming computer (I upgraded from a Core 2 Quad Q6600 with 8GB of memory, which was decent in its own right).
It hurt a lot to spend that much money, but I was comforted by knowing that the only way to get a significantly better processor, I would have had to spend over $1000 more on a Xeon and $200 more for a C602 chipset server motherboard. I am also comforted every day knowing that the x264 transcodes done by the Mint Linux x64 VM running MythTV would take much longer and would have eaten more than half of my system's performance if I had saved $300 and gotten a 3770K instead. My MythTV VM is set to use 2 cores (that is, 4 VMWare vCPUs, or 1/3rd of my system's CPU power) and I give it 8GB of memory. It doesn't noticeably affect the performance of the Windows 7 Ultimate x64 host it is running on, even when I'm trudging through a large Photoshop file or playing around in AutoDesk Inventor Pro.
I am a terribly impatient person, and spending that extra $300-$400 has proven itself worthwhile to me. If you have the patience to set up your encodes to run overnight or if you can wait the extra several minutes or more to let your system churn away at a huge render process, then the 3770K is a worthy, capable processor. If you can't stand not having your computer ready and waiting for you, then you'll be willing to spend the extra money on the 3930K. If you are a shrewd operator, then you might recognize the wisdom in getting the 3820 now, which might not give you all the performance of the 3770K, but offers you quad-channel memory bandwidth now and an upgrade path to Ivy Bridge-E sometime around next summer.