How can I get Armenian language support in iOS?
iOS does have an Armenian font and can therefore display Unicode Armenian in emails, webpages, and text.  For input there are at least two apps that let you construct custom keyboards, and one of them, UniKey, comes with Armenian already:

http://m10lmac.blogspot.com/2011/05/custom-keyboards-for-ios-devices.html

Beyond that or jailbreaking, I think all you can do is ask Apple to add it via their feedback channel.

PS To see Armenian display on your iOS device you can go to

http://www.gov.am/am