As it turns out, going from the simplest cruising to real walking is a lot more of a transition than we initially imagined. As time went on, Christophe got increasingly stable with his standing and cruising, learned to transition across all sorts of gaps and learned to squat and stand without support. In the meantime, he also perfected rolling and crawling, to the extent that he'll often drop down to crawl longer distances that, once upon a time, he would have cruised.
Fairly early on, Christophe would occasionally take a step or two without support, to do something like cross a gap that was just a little too far for his reach, although even that was hesistant and rare. In the last month or so, that kind of gap-crossing has become more common, although he's still shown very few signs of generalized walking.
I try and encourage him gently -- call him to me across a space he can't cruise, that sort of thing. So far, that mostly results in either him not crossing the gap, or choosing to crawl the distance.
Yesterday afternoon, Christophe stood without support, not very near any potential cruise target, holding the (non-functional) remote control we'd given him to play with. As had become habit, I backed up a little to give him some room and called him over, and he began to walk without support towards me.
I wasn't prepared for how exciting and emotional that would be, particularly since he's come so far. Between the rush of emotion in seeing him walk, and trying to praise him, encourage him, and call Pierrette to see all at once, I'm not entirely sure of the specifics, but I'd say he walked about six or seven steps before stopping and then probably either squatting or falling relatively gently to his bottom.
Later that evening, I was able to persuade him to take a few more steps, but he hasn't shown any signs (so far) of breaking into regular walking. I'm sure that someday soon, Pierrette will be calling me to tell me that he has walked an even longer stretch, and I'll be jealous that I'm stuck at work.
Exciting times. We'll try and catch his early steps on video soon.