I dispute the first graf for three reasons. First, the attack (you can play with it yourself; it's one of our upcoming crypto challenges) is relative to the start of the art in cryptography devastatingly easy to carry out; it takes a large amount of time, and may not be suitable for mass attacks, but one can imagine circumstances today in which this attack could be workable for targeted high-value secrets. Second, the kinds of advances in this attack that will make it more viable are less likely to be cryptographic and more likely to be systems programming related; as people play with the attack and explore more of the interactions between browsers and (say) specific RC4 bias positions, I think we're likely to find "non-cryptographic" (to coin a term) refinements of the attack that will make it scarier. The tempo of these kinds of advances is much, much faster than the tempo of fundamental advances in crypto. Finally, I think that graf doesn't adequately capture the other circumstances in which RC4 is used --- it's not a hair-on-fire operational issue for the web today, but it might be hair-on-fire for less well-understood cryptosystems.