My son is a bit over 8 months old, and I still have to swaddle him, too. I've thought about trying to wean him from the swaddle, but frankly, I'm too exhausted to deal with a potential lost nap or middle of the night wake-up. We started swaddling him at about 10 weeks, due to what I call "crazy arm" syndrome. He'd bat at his face and couldn't get to sleep unless we held his arms down. A friend introduced us to swaddling, and it worked wonders (he almost immediately went from 3-4 hours of sleep to an amazing 6+).
Now, at 8 months (and an amazing 12 hours of sleep at night!) Jack can get his arms out if he wants to. Every once in a while if I go in his room before he's awake in the morning, I'll find an arm or two out and he's still half asleep. He's even fallen asleep for a nap recently after having wiggled out of the swaddle while I was out of the room for a few minutes letting him settle. I was so surprised when I went back in to check and he was sleeping with both arms and one leg out.
I worried when he started rolling over to sleep on his belly, but he's shown me his amazing rolling while swaddled abilities (which he seems to be quite proud of) and he's quite agile!
I do worry too, about getting him out of the swaddle. But, I think he's getting closer to where he'll just stop needing/wanting it. I don't think it's a prop for him. I think it's more like part of his wind-down ritual--a comforting cue that it's time to sleep. It's spring here now so I do hope he'll grow out of it soon, because it's going to get too warm for the fleece swaddle we use.
Margaret, I think I'll try the sleeping bag like you mentioned for night soon. I think that will work well for us, but that it will take a while longer to remove the swaddle for naps.
Jack's still got a bit of his "crazy arm" syndrome. . . but I have noticed that he's starting to be able to fall asleep with a hand up by his face. He'll sometimes gnaw on his fingers (teething, likely), and I think he can soothe himself that way now as long as he's not overtired. Even just a few months ago, if he had a hand by his face, there was no way he was going to sleep.
You're not alone, Marie-Claude! I hope others will post their swaddle weaning stories. I'm interested, too. (We don't want to be swaddling 5 year olds, do we?