I'm not hugely upset because I've been in this position before with conventions when people have had to pull out because of work commitments and while it is disappointing, it's great for them and the convention is no less great fun for it. Prime, anyone? I was pretty gloomy when Nick Brendon had to cancel and then getting there to find out that Jonathon Woodward hadn't shown up (neither had Tom Lenk but I could have cared less about him... *miaow*) but you know what? I had an absolute blast that weekend and when JW (and Tom Lenk) did show up on the Saturday we'd already had a great time.
Because conventions aren't just about meeting the stars of the show. They're about meeting you guys, about sharing in the love of a show, about sharing the squee.
(Plus, Jensen Freaking Ackles is still going to be there, and now we get Nikki Aycox as well - plus the lovely Jason Manns. This is still going to be a fantastic convention. Trust me.)