Great news! YouTube increased its upload limit to 15 minutes for all users of YouTube! Here is the official blog post about it.
On a funny note, apparently the reason that videos have been limited to 10 minutes is in an attempt to limit the amount of copyright infringement on YouTube; for example, if there were no limit then users would upload full length movies to YouTube. Of course, plenty of full length movies already exist on YouTube, split into 10-minute chunks, so this limit obviously did no good on that front.
I'm very excited for this raised limit, and it comes at a great time: a couple of my screencasts for my current project are just over 10 minutes. Now they will fit perfectly once I add intros to them! I was fretting over how to split them up but my problems are solved. Now I just need to figure out how to split the one that's over 15 minutes (!).