You Can't Fake Good Character
I agree with Ezzie completely. There is no place for this kind of behavior - it is just plain wrong.
Many people who want to defend DovBear have made the claim that "he just plagiarized a little" or "people are taking blogging way too seriously", perhaps rationalizing his actions because they personally enjoy his blog or agree with many things he has said in the past.
They ignore a very important fact, though. Your character (you can also use the Hebrew term "middot") is judged not only by the big actions but by the small ones too.
Yesterday, the lady at the makolet, perhaps because of the Friday morning rush, forgot to ring up a can of pineapple that I had bought. I noticed that she had forgotten while still at the register, and pointed it out to her. She quickly put it in, and I paid. The can cost all of eight shekels (less than two dollars), but for me it didn't make a difference. Stealing eight shekels from the grocery store is the same as stealing a greater amount.
Your character is shown by other actions too. How do you treat the people who work for you - even if just for a short time? Do you say thank you to the waitress in a restaurant, or to the cleaning woman in your office building, or do you treat them as if they are part of the furniture? Do you say "good Shabbos" to people on the street, or at least answer them back when they greet you, or do you just walk by? (This is one of westbankpapa'a pet peeves when in a certain Charedi neighborhood in Jerusalem - only rarely do people answer his Shabbat Shalom with a similar greeting).
In terms of the blogging world, your character can be judged here too. Do you answer your commenters? Do you respond civilly to the ones that disagree with you, even if they themselves are less than polite? (This does not mean the trolls - the people who are obviously just trying to "make a scene" and are not interested in a rational discussion should be ignored). Do you steal others' words or not?
You really can't fake good character, at least not in the long run. A slick salesperson may be able to do so to get a quick sale, but this only works for a short encounter. In any other situation, where people interract for a longer period of time, the real you comes out.
Yes, blogging is just a hobby (at least for most people). We don't need to take it too seriously. But if you think of it as another place in which your character is on display, then you should take it seriously indeed.