According to the EU and US PS blogs, the PS Store is now back up and running, you can purchase items as normal now, so I will be redeeming my DLC codes I got with brink.
Anyway, there is also some bad news, the “Welcome back” content is not yet live as Sony have to test it first. (Although why it needs testing is a mystery, personally I think Sony are buying time). This is not much of an issue as the Welcome back content is mediocre at best and not really worth the HDD Space.
My advice is to leave the PS Store for a few more days, so that it can calm down a bit as imagine all the users trying to download stuff all at once.
Oddly though PSN never went down for me, even after 4:30pm when I signed in I could still play online so whether the store is back for me remains to be seen.
Anyway thanks for reading.