We'll have to wait until  replies to this and we hear what he has to say about that (he's the most knowledgeable person on this subject). Until then I guess we could start a list just for fun. 

 List of notable Tajiks (from all countries) 
 Politics 
Abu Muslim Khorasani
Ahmad Shah Massoud
Latif Pedram
Abdullah Abdullah
Yunus Qanuni
Burhanuddin Rabbani

 Arts and Science 
Rumi
Avicenna
Biruni
Rudaki
Al Khwarizmi