"Only" 75 hours, where you have to force the victim to do make a very large number of encrypted messages. IMO, this wouldn't work when trying to break someone's SSL connection at the local Starbucks.
If I had a dime for every penny of damage caused when people downplay the practicality of attacks against deployed crypto...
75 hours is enough time to attack a laptop left plugged in at the office over a 3-day weekend, and there's no reason why you'd have to attack only one laptop at a time.
The paper also says, "capturing traffic for 52 hours already proved to be sufficient", so it's not like 75 hours is some hard minimum.
Also:
"Our attack is not limited to decrypting cookies. Any data or information that is repeatedly encrypted can be recovered."
"We can break a WPA-TKIP network within an hour."
RC4 is dead, dead, dead. As with MD5, the writing's been on the wall for a while now, and attacks are only going to get better.
But if a couple guys can break something in 75 hours, knowing crypto attacks only get better, you can already consider this broken.