I try not to stop reading too early. Drudge is not a journalist. Indeed, I have seen at least definition of "journalist" (a "reporter who writes for an editor") that was described in the source I saw it in as an explicit exclusion of Drudge from the ranks of journalists.

A blog post, "Blogs lead in critical thinking, but newspapers still matter,"

http://www.dcscience.net/?p=6083

submitted to Hacker News earlier today to no discussion,

https://news.ycombinator.com/item?id=5907627

illustrates some of the reach that "traditional" journalism still has. The quality of professionally edited journalistic submissions to HN, as contrasted with the quality of many (although not all) blog posts submitted here, suggests that there is still a role for journalism in promoting more informed, more thoughtful discussion of issues we all care about.

How is a news aggregation site considered journalism?

I would have a hard time calling the largely news aggregating Huffington Post journalism even though it has original content. Or at least serious journalism with some kind of journalistic integrity.