Blizzard issued a response regarding the inability to access Battle.net or World of Warcraft servers from Iran. According to the post, the issue stems from applied US sanctions instead of government bans on specific content - although the latter is still true as well.
"This week, Blizzard tightened up its procedures to ensure compliance with these laws, and players connecting from the affected nations are restricted from access to Blizzard games and services.
"This also prevents us from providing any refunds, credits, transfers, or other service options to accounts in these countries."
WoW isn't technically available in Iran, but those who play the game in the country use virtual private networks in order to access the game. While this is against Blizzard's terms of service, as has been noted before, it happens in other places as well and not just for playing World of Warcraft.
Other titles which seem to have been taken offline in Iran include Guild Wars, RuneScape, Second Life, Dofus, Evony and Entropia Universe.
Blizzard apologized to those affected by the service being cutoff, and said it "will happily lift these restrictions as soon as US law allows."
Thanks for the head up, and sorry: GwynbleiddiuM.