Just a friendly PSA...
[Update: Sony has temporarily pulled the troublesome patch and is investigating the problem.]
PlayStation 3 owners looking to use the system's online features this evening may have already noticed a prompt to download the latest firmware update. Do not accept it! Reports are coming in that suggest the latest update is bricking systems.
Of course, the issue isn't universal. Not everyone is being adversely affected by the update. However, it's probably better to be safe than sorry. PlayStation 3 users might want to consider other avenues for entertainment until this mess gets sorted out.
Problem after update to 4.45 [PlayStation Support]