Nowak -
There isn't a fixed time frame that I've seen.
It's usually about 1-2 weeks after the release has gone GA.
The 8.2.1 GA sim is available for download now.
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff
Independent NetApp Consultant, K&H Research http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, Unitek Education http://www.unitek.com/training/netapp/
(P.S. I appreciate points for helpful or correct answers.)