It's clear the new 2011 MBPs run hotter and louder under load than the 2010 ones. 1. Per the system specifications, the quad core processors have a 45w TDP vs last generation's 35w TDP--that's a big increase. 2. The fans top speed has been increased on the 2011 models to 6500, which I believe is unprecedented--I've never heard of an Apple laptop that used more than 6000 rpm as a maximum. Certainly the 2010 models maxed out at 6000 rpm. There is plenty of anecdotal evidence available on this forum and elsewhere, which I won't link to or refer to here as some have better methodologies than others, but the best comparisons come to the same conclusions--when doing the same work, anything that is processor or GPU intensive, the 2011 models will get louder and hotter than their 2010 predecessors. Also anecdotal, but it is worth noting that 2010 MBPs are assembled with the same lack of care with regards to the amount of thermal paste...but it is only with the 2011 models that a large number of hacker types are willing to risk voiding warranties by improving the paste application. The clear implication is that with the 2011 models their are a higher number of users investigating making changes because their laptops run hotter and louder. If you are bothered by heat/fan noise, here is what I recommend: 1. Wait for Ivy Bridge, the die shrink of Sandy Bridge, which is in the 2011 machines. Ivy Bridge should refine Sandy Bridge, and specifically run cooler--every other MBP after an intel die shrink/refinement has been the generations that ran "cool". It is a bit of a wait--Ivy Bridge is probably coming to the MBP in 2012. 2. Buy a 2010 model. They are still available, on sale for large markdowns, and still great machines. Yes, you miss out on a few great upgrades (Thunderbolt, high-res iSight) and the awesome quad core processors...but you also don't have to deal with the noise/heat of awesome quad core processors. 3. Investigate for yourself...but be aware that if you are the kind of person who is bothered by heat and/or noise, be alert and do not expect miracles. There will be no special firmware from Apple in the future that changes everything--45w TDP is 45w TDP. They can only make it cooler by ramping fans faster, which makes noise, or by turning down performance, which is unlikely and will upset a lot of people. If it bothers you a lot when you buy it, you may need to reconsider your purchase, depending on your needs. 4. Do you need a MBP? A surprising number of people who traditionally get MBPs but don't task them heavily may be better served by a maxed-out 13" MacBook Air...which will be much much cooler, and absolutely silent. Make sure you've re-evaluated your needs in light of Apple's evolving product line--the MBA is a killer laptop if it suits your needs. I wanted to post this to present a rational, measured voice about the situation. No one is denying the 2011 MBPs are fantastic machines--between the quad cores and Thunderbolt, they are the closest we've been to a desktop replacement ever. But power comes at a price, and for this generation the price is heat and noise under load.