Why give the recipe at all?
On eGullet, many people write about cooking from different books (type "cooking with" into the search area at the top of the screen). Check out how they write about recipes, see what fits your style and emulate them. If I wanted to be a successful blogger, I'd be looking more at how other successful blogs work and copying and adapting their style to my own rather than considering including the recipe.
Why include the recipe? Because many readers, and I count myself among them, are probably interested in what the recipe indicated you do--if you said you needed more milk than called for, I want to see how much was called for, how much water, eggs, flour, etc. If it gives me the opportunity to try to emulate what you did, all the better.
At the very least, I don't see how including the recipe could be detrimental
to a blog post--recipes and good posts certainly are not mutually exclusive. Maybe it's the scientist in me, but when I read about recipes and techniques, I want to be able to think about them independently, question the author's assumptions, experiment on my own, etc, and this means trying to get as much info as possible. Sure, you could
say, "well, go buy the book," but why make it harder for your readers than necessary? It seems totally stupid to have a blog with an entry about "Totally Awesome Way to Make Noodles with Xanthan Gum" and then say "you have to try this, just buy the book to find out how." At that point it's a teaser for the nightly news, not something I'd be interested in.
The "Cooking with" threads are a little different, because they're organized naturally to appeal mostly to the owners (or probable future owners) of the cookbook being discussed. I suppose a blogger could similarly limit his/her audience, but that seems unnecessary.