Does anyone know what will happen to Alexandros Mograine and Uther the Lightbringer? They were cool characters. Bolvar was cool too, sad that all greatest paladins are dead now :(
Mograine and Uther are dead and will stay dead. Uther's ghost will probably continue to still spring up from time to time doing his Obi-wan impression but in terms of story, there isn't much left for the original Knights of the Silver Hand. Their stories have been completed. Blizzard will move on with new stories and new heroes.
Other than Tirion Fordring and Turalyon (who is one of the few old heroes still MIA), there are new paladin heroes moving coming through. Leoric Von Zeldig and Grayson Shadowbreaker seem to be fairly important paladins that are still active. I wouldn't be surprised if Arator the Redeemer (son of Turalyon and Alleria) did something herioc at some time.