One of the worst parts of uploading to YouTube, especially large and long HD quality videos, is waiting for YouTube to finish processing the video so people can watch it. I normally create a 15 minute or so video, in HD quality, upload it sometime before 11am to YouTube and it often won't be available until after 6pm. The upload process takes an hour or so and the processing can take several more hours.
On very limited occasions, those videos never make it out of the "in processing" status and then you have to reupload all over again. Never fun.
This time, Liz from the YouTube support team has confirmed a bug in the upload process. She posted a thread at YouTube Help the other day saying:
Some of you have mentioned here in the Help Forum and on Twitter that your uploads are stuck processing. This is a bug with the uploading process and our team here is currently working on a fix. Once the team's fixed the bug, uploads which are currently stuck processing will be re-processed again.
For those of you who need to upload a video immediately, try uploading a second time if your original upload attempt is stuck.
Thanks for informing us of this situation, and we appreciate your patience while we're working on resolving the matter!
It is nice to know YouTube is looking into the fix.
Forum discussion at YouTube Help.