If you're patching on Steam in the wee hours of the (Pacific Time) morning with us, please note that there is a followup patch to the 200mb. This followup patch is 40mb and will correct an issue where error dialog appears on login (and other actions.) If you're receiving these errors, exit the client & Steam, then restart Steam to download the quick update.
Not sure if you have the right version? Check the bottom left of your login screen! If it says SHIPPING, you're good to go! If it says INTERNAL, exit the client and grab the download.
If you're coming in later, Steam will have caught both for you. :)
We'll be bringing down the Marvel Heroes servers tomorrow morning at 6AM PDT for game update 2.35 featuring Doctor Strange and the Black Panther level 52 design review!