Because its an Enterprise 2.0 account, you can do the following, using the subscriber system view (see more info at Data View: Subscribers):
%%[
var @name
SET @name = "dude@exacttarget.com"
SET @status= Lookup("_subscribers", "status" , "EmailAddress", @name)
]%%
----- New EXAMPLE-----
Something I have using AMPscript in a clients code... may be useful here
SET @rr2 = CreateObject("RetrieveRequest")
SetObjectProperty(@rr2,"ObjectType","Subscriber")
AddObjectArrayItem(@rr2, "Properties", "ID")
AddObjectArrayItem(@rr2, "Properties", "EmailAddress")
AddObjectArrayItem(@rr2, "Properties", "SubscriberKey")
AddObjectArrayItem(@rr2, "Properties", "Status")
/* Create a filter be the subscriber Id */
SET @sfp2 = CreateObject("SimpleFilterPart")
SetObjectProperty(@sfp2,"Property","SubscriberKey")
SetObjectProperty(@sfp2,"SimpleOperator","equals")
AddObjectArrayItem(@sfp2,"Value",@email)
/* invoke the Retrieve Call */
SetObjectProperty(@rr2,"Filter",@sfp2)
SET @atts = InvokeRetrieve(@rr2,@status)
Then I loop through the results
According to SFMC Support, there's no way to do this.
My workaround has been to retrieve all of the lists for a subscriber. If all of them are unsubscribed, then the overall status is unsubscribed.
Best Answer
There are two ways that you can approach this.