It depends. If you want a new playtrough you could start now as i don't think there are any major bugs related to new games, only saves carried trough many patches might suffer.
However, if you want more content than at the moment i'd suggest waiting at least for the next week as there is a chance we'll get a new beta patch with many new things(don't go mad if it doesn't, i just speculated as mexxico said the changes are already in).