Are you enjoying the wild weather here the past few days? Looks like more for tonight. I hope you didn't lose power for long or have water damage.
I put writing samples on my blog all the time because it's a kids' blog (kinda like a kids online magazine).
However, none of the writing on my blog is writing that I hope to publish or that has been published (since I'm not yet published).
If I were published I would only put samples online from the published books after getting advice from the publisher.
Personally, I wouldn't want writing that I hoped to publish to feel 'familiar' to editors. I don't even mention work that is out on submissions. Besides, to me it looks a little presumptive. (like I'm promising the full text will be published)
The risk with putting unpublished writing samples online is that the writing may not be as well edited. You still need to let it sit, polish, have someone else read it, etc.
I might be 'wrong' to put writing samples on my blog, but I'm really enjoying it, there is the chance I might never get my 'regular' work published anyway, and for better or worse, it's 'me'.