I would see that eventuating if this allowed commenting via the embedding blog, thankfully it doesn't. I don't have the same issue with this that others do, but I remember TheNextWeb getting a bit of slack from commenters for embedding HN comments (although that was mixed amongst other comment platforms, and is a little different)

API-wise, http://api.ihackernews.com/ , http://hndroidapi.appspot.com/ or http://www.hnsearch.com/api didn't suit? [edit] what am I thinking, an API doesn't need an API...

Oh, and simplicity of this seems pretty nice!

Probably not, unless your blog has an organic audience that is bigger (or at least comparable) than that of HN homepage...