My own blogging (and commenting) activity waxes and wanes. There have been a few times when I’ve wondered if I’m losing my motivation, but then I go through a phase when inspiration strikes more often and I end up updating multiple times a week. It helps that I’ve never set any constraints on what I blog about, and have never been shy to post a quick-and-easy photo and caption or other short post. I can definitely understand why people who stick to a narrower set of subjects, or who always post long, thoughtful posts, would start to feel uninspired after a time. But for me, there’ll always be some new research findings, political shenanigans, hockey games, and silly cat photos to post!

Thank you for the comparison with Pharyngula, but I am afraid the blogging equivalent of the late Lloyd Bentsen would go “Massimo, I know PZ Myers… PZ Myers is a friend of mine… Massimo… you are no PZ Myers”.
On a more serious note, I have been asked to write more about physics, and I guess it is an idea but there are two problems:
1) I still have to let go of the tiny little bit of shame of which I am unfortunately still capable. The problem is that I know just enough physics to realize how much more I should know, and that makes me hesitant. But you are right, I did write a few physics posts and they were reasonably well received (nowhere near as well as my all-time hit, though — I am talking swiss laundry machine, if you know what I mean…)
2) I do not dislike Brian Greene per se, he is an excellent popularizer, and I suppose his documentary may have gotten someone interested in physics (I doubt it), but the point is, it is much easier to popularize something when it is not even clear what it is. At that point, the line between popularizer of science and TV evangelist gets really blurry. Popularizing what I work on is not easy because it requires some basic understanding of quantum mechanics, and to make that accessible is something at which even R. P. Feynman failed (in my opinion).
But you are right, I could try. After all, it is not like I have not made a fool of myself in the past (swiss laundry machine anyone ?)

For me, we had our second child and that was pretty much the end of blogging… and reading books, and watching baseball on TV, and eating out, and going to movies, and traveling…

For what it’s worth, I hope you keep at it. I always look forward to your posts, even though I don’t always comment (Often it’s late, I’m in bed perusing on my iPad, baby sleeping on my chest – not so easy to type). I even slog through the more esoteric physics stuff. On the other hand, the stuff on Canadian politics goes straight out the window (you all have free health care – what the hell else do you have to complain about?).

Blogging is rather ephemeral, isn’t it? Bloggers come and go. Blog posts disappear from the bottom of the page, rarely to be revisited. Some points:

1) I don’t think you should worry about redundancy. Look at PZ Myers. He basically has one point (there’s no God), and hammers it home post after post. Readers come and go – if you revisit a subject, I suspect a lot of fresh eyes will be reading it.

2) If you need blogging ideas, here’s one. How about some physics for the rest of us? I remember you writing about how much you disliked the Brian Greene documentary on PBS. Care to expand? (But for God’s sake, no math). I suspect that it would be challenge to write for a lay audience, but it might prove interesting. You’d have to push into areas beyond your comfort zone, and simplify your prose (without getting stupid).

IMHO, what you do now – i.e. writing essentially for your fellow sciencey academics – is just too limiting; limiting in terms of subject matter and limiting in terms of the audience you can reach.

It’s time for you to conquer the world (since you have all this free time…)!