Yeah, back when CPUs gobbled 130W and didn't have much in the way of frequency and voltage scaling you needed a fair chunk of heatsink and the fan need to do a fair bit of work. Nowadays they pull much less on load, idle super efficiently, and have enough power to do most things a desktop needs to do without too much effort. That's why people are getting away with super compact ITX systems with 4790K's and Titan X's.
Take the Dan A4-SFX case for instance:
http://hardforum.com/showthread.php?t=1799326
They haven't got the manufacturing agreements sorted out yet, but it's a thermally valid design that takes up a tiny amount of space but packs top end hardware, and since each major heat producing component has its own thermal zone and fresh air intake, it doesn't need case fans, just the fans attached to the hardware is enough.