I'm not opposed to the idea in general, and I'm not opposed to being physically close to people I just met. However, my interest would largely depend on the atmosphere and the rules.
For-profit commercial things at a convention I probably wouldn't be into. If there was a small cover charge to offset the cost of renting space or providing refreshments or something that would be fine, but setting up a cuddle orgy to make money seems somewhat creepy to me.
As for atmosphere, I would not be into it if it was a "by taking part you are consenting to cuddle with everyone here" kind of thing. I need to be asked first, and be free to decline, or to say "let's talk a bit first," and I wouldn't be comfortable unless others are free to do the same.
If these conditions are met it would probably be something I'd be into. If I ever chose to go to one, I'll have to do some research into the particular event before deciding to attend.