Vine will be rolling out personal URL (e.g. http://vine.co/USERNAME) as soon as tomorrow. However, they will start with those who had verified account on Twitter. the rest of us will have to wait until 23rd December to register for it.
To many people, this is not something important. However, it will be good to have the same username for most of your social accounts (my opinion).
So, on Monday next week, remember to register for your vanity URL for Vine.