I'm torn as well. On the one hand, I feel kind of like Maieshe said. I wouldn't buy a subscription to read the article. Therefore, if I read it, I'm not costing them anything. On the other hand, I know I may just be justifying the behavior. There is a valid argument that reading it without paying is either stealing or it isn't, rather than it's not stealing if x, but it's stealing if Y, depending on your personal ethics. Is it not stealing if I steal a loaf of bread because my family is starving, but it's stealing if I steal a TV because I don't want to pay for it?
Christopher makes an interesting point as well. Are property rights different, or more or less valid than intellectual property rights? I'm not sure.
There was a time when I would download books, music, or software, and "trial" it. I did it without the seller's permission, but I was meticulous about then paying for it if I felt it was worthwhile. I don't do it now. Now if I want access to someone's material, I purchase it and take my chances. Or, I do what I did with Matt Walker when I was interested in his stoves. I sent him an email and asked if he would send me one page of his instructions so I could get a feel for what they were like and if I could understand them. He graciously agreed and sent me a page. I read it over and purchased his plans. That seems like a win/win to me, and it works great in a smaller community like this. It probably wouldn't work as well if I wrote Stephen King and asked him to send me a page of his new book.