The latest and greatest

Sometimes I see a new product (in this case speakers) that get lots of press and discussion only to see lots of them for sale a little later. 
Right now there are many pairs of Kef LS50s coming up for sale (both the regular and W versions).
Are these just a flash in the pan or just showing up on the market because so many have been sold?
In my mind there is nothing like a product that has stood the test of time. 
Am I just being a sceptic?