I was on my way here to post a link to a guest blog I wrote about "Must-Read" fantasy books, when I ran smack-dab into a couple of highly relevant pieces on, essentially, the problems of genre. Jo Walton wrote a great post on SF's problematic aspects as a genre, which I thought was well-done and brought up a number of points about how we both categorize and stigmatize stories. I no sooner read that than I saw Cat Valente's long excoriation of steampunk on her blog. Both are strongly-argued discourses on the problems in the definition and application of the bundles of tropes and ideas that constitute a delineated genre classification.
They are also both noteworthy for the way that they show the effect of sociality on genre. The nigh-inextricability of SF/spec fic/fantastika from the socio-cultural trends and practices of the moment comes to the forefront in both pieces, albeit in different ways. Walton argues that SF is a sponge that is sensitive to the world around it. Valente takes steampunk to task for being too much about the social and the aesthetic, and not enough about the writing or the stories. While coming from different angles, both pieces trenchently take apart commonly-reproduced assumptions about genre. Which I find to be edifying, as discussions like these push me to look more critically at my own writing.