Now, because "your creativity isn't bound by a time limit", you can upload videos of any length as long as your account is in good standing.
As long as your previous videos have not violated YouTube's Community Guidelines, you can now start posting longer videos.
However, if you start uploading copyrighted movies and stuff, YouTube will detect it automatically using their Content ID system as usual, which has been there all this time.
[via The Official YouTube Blog]
