To convert a ISOString into a Date object, use dojo.date.stamp.fromISOString. For example:
var dateObj = dojo.date.stamp.fromISOString("2011-04-26T19:30:40+0000"))
To convert a Date object into a localized date format which you would like, 3 parameters I regularly tend to use are “selector” and “formatLength” and “datePattern”:
dojo.date.locale.format( dateObj, {selector:'date', formatLength:'full'} ) //returns "Tuesday, April 26, 2011"
You can also specify different datePatterns like datePattern: “yyyyMMdd”, etc. More details here.
A useful link for confirming to regular cultural conventions here.