Steve Chen, a co-founder of YouTube, confirmed that high-quality videos will start appearing on the video-sharing website within three months. Plus making video content available to everyone globally requiring low-bitrate streams is a major priority.
Steve Chen told CNET that current resolutions of YouTube videos were good enough for the site until now and that high-quality YouTube videos will start to appear within 3 months.
Chen also confirmed that videos uploaded to YouTube are stored in the original resolutions that they were uploaded in. This should make compressing into a high resolution somewhat easier.
It would have been more difficult if they were taking the low-quality videos that are used on YouTube and converting those into higher resolutions.