The chaps over at MadShrimps have published CPU Heatsink Round-Up. There are seven heatsink all together with Thermaltake, Spire, Aerocool, Tuniq and Scythe all having dogs in the fight:

My conclusive thoughts haven't changed from the last roundup, if you want a silent, yet speedy PC with enough CPU power, you'll have to invest in third party cooling, especially when you are into overclocking; the stock heatsinks just don't quite cut it.

There were an interesting few additions this time around, offering excellent performance/noise ratios, easily installation and multiple platform compatibility. Manufactures are working hard producing products which meet all the demands from enthusiasts out there, making a silent, performing, easy to install heatsink which fits multiple platforms and doesn't cost too much to produce is not easy at all. The different approaches each have their advantages and disadvantages; but it's clear that this market is far from dead or stagnating.