Well, this is where I'm torn. The 4770k and the 4790k both use the z97 chipset, so I can use the 4970k on the z97 motherboard that I already have. If I go with the 4790k now, it'll last long enough that I can just skip broadwell all together, and not have to get a new mobo.
Like I said, I haven't even opened the 4770k yet, so I can probably sell it for like $10 or $20 cheaper than stock (I hope.) I wouldn't mind paying 20 bucks to get +500MHz and in the long run, I'll be saving money skipping broadwell. Since I got the 4770k for $250, that's an $80 discount. If I sell it for $320, that means I can buy a new DC i7 for 20 bucks.
Oops, turns out Broadwell will actually be based on the 9 series chipsets. That's good, I guess.