Honestly the best thing anyone could do is quit trying to log on. The more people pounding the service trying to log on and buy shit at once the longer its going go take Sony to get PSN up and running.
You should wait. I only say this because apparently with the 2.0 firmware it causes dragon age to corrupt save files. There were multiple ps4 reviews that mentioned this. A launch day patch fixed this but without the patch there is a chance you could get a corrupted save.
@euandewar: Depends on how you're connecting if you're connecting directly to the PS4 then no you should be fine. If you're connecting through wi-fi then I'd say there might be a chance that would affect it.