In reply to JdotP:
have spent a fair amount of time there and have lots of good contacts within the country (including family and UN).
unless youre involved in moving stuff across borders or journalism in sensitive areas (parts of the pamir alay and the uzbek border) theres nothing general to worry about. maybe the occasional macho russian or drunk in dushanbe or some of the border towns, but not like at home.
my parents, both in their mid-60s regularly travel to tajikistan and spend half their time out in the towns away from dushanbe, so theres an indication if you need it.
be careful tho of things like open drains, dogs and dark streets in towns at night. its still pretty wild west, and a hard place to get out of quickly if you have an accident.