Yep it takes a long time. Espically in 720 or 1080 HD. 480 isn't horendous time. But the data preparation takes a long time regardless.
Mainly just set up the computer's settings to never go to sleep or go to screen saver or anything when plugged in and walk away from it. Good tip especially when upgrading operating systems or defraging a hard drive.
A lot of the people who do youtube as a career will start uploading a video before they go to bed or as soon as they wake up. Or they could be doing it in the background as they record or edit if the computer has enough processong power and the internet is good enough.