http://www.gizmodo.co.uk/2011/12/how-the-hashtag-is-ruining-the-english-language/

Some interesting points made here, one being that hashtags are somewhat the equivalent of verbal tics (people who say 'like' or 'y'know' constantly without being aware of it).

The other point I really liked is that hashtags are similar to emoticons, why write something in a way that implies how you feel when you can just drop a hashtag on the end?

#hashtag