TWC has had a few really good blogs about the value (or lack thereof) of seasonal forecasts. One of my favorites, punched out by Stu Ostro, can be read here.
In general, it is my observation that by far most of the scientists issuing these forecasts are doing so in the name of science, and of trying to get it right.
Some of these experts also seem to take the public's perception more into account than others. Often this is because they are explicitly or implicitly tasked with such consideration. For example, the NHC issues a relatively wide range of numbers of storms, hurricanes and majors, and makes an effort to stress to the press and public not to pay too close attention to an expectation of any exact number... or exact point of landfall.
For the most part, the scientists do not hype. On the other hand, many in the 24-7-365 modern-day media, do. When a seasonal forecast is issued by an expert scientific body calling for "much above average" numbers of names and/or hurricanes and/or majors, not half-way through the dixie cups and string of Internet transmissions, misprints, media exaggerations, water cooler conversations, etc. ad nauseum, often the consumer at home is already left with the impression that those seasonal forecasts are calling for Armageddon.
So far for 2010, we have just passed the climatological high point of September 10. With nearly 50% of a typical season left to go based on climatology, we are at 9 officiated Storms, 4 Hurricanes & 3 Majors.
As I have suggested above in an earlier comment, there is a huge drawback to comparing seasonal totals in real-time to past years. This is simply because the listed numbers in prior years include post-season reanalysis.
Once a year is up, sometimes even many years later, additional information exposes storms, hurricanes and/or majors that previously went unidentified, most likely due to the limitations of trying to accurately identify each and every system in real-time, which by its very nature, requires one to assimilate a massive volume of data, very fast, and still be 100% accurate - a ginormous task even for the very best super computers, let alone mere humans.
If one wanted to even use just some very simple math and double the current numbers to reflect the roughly 50% of an average season still left to go, then one could extrapolate a 2010 season total of 18 names, 8 hurricanes & 6 majors. Or, knock 10% off to allow for the fact that we are a few days past the peak, and "forecast" a total of 16 names, 7 hurricanes & 5 majors - which is still way above the long-term average, by the way. Or, allow for the fact that post-season reanalysis has yet to be done, and add 10% to the original extrapped totals and get a seasonal forecast of 20 names, 9 hurricanes & 7 majors - way, way above the long-term average.
In reality, nobody knows what will ultimately happen over the coming weeks and months. But seasonal forecasts do have some value - more often than not they have some degree of accuracy. However, it is up to us to closely pay attention to what they are actually saying, and not let others misrepresent them to us.