Wildstar is going F2P on Tuesday 29th 00:00 EDT (6am our time).
If you already have an NCSoft account (Aion or Lineage), you’re good to go, otherwise you’ll need to create an account. You can download the client so long , but bear in mind that according to the linked article, there will be a sizable patch on the 28th for F2P.
Initial download size for standard client is 19653Mb. The PTR was around 12Gb.
There are new realms at the moment, if you hadn’t noticed. There’s a Jabbit-2 and a whatever the PVP is -2 as well.
The first post in the thread above answers questions about it, such as what happens when the realms merge back in to one again, etc. Quite interesting.