the biggest thread for reading on the web is - in my humble opinion - the swipeware deployed on multiple small and big sites (i.e.: all *.wordpress.com blogs) for mobile devices like the iPad. swipeware has a horrific user experience, adds nothing of value to the page or the article and makes it impossible to read an article from start to finish.
out of curiosity: is there anybody out-there who thinks swipeware on blogs is a great idea/experience?