In terms of predictions, I have always thought the IlClan era might see all the I.S. Clans become one-mega Clan, the IlClan, with all the component parts inside (There are still internal Khans, who operate the Clans like states with the IlClan being a very strong federal-style of government). I remember the Devs mentioning wanting to simply the factions down, and we see that happening with a number of factions. Then they could have The IlClan in the Inner Sphere, with an IlClan in the Homeworlds.
Capellan Confederation + Canopus + Andurien (Dania Centrella-Liao being the heir to all 3)
Republic + Fed Suns (Mention of a Government in exile in TRO3150)
All the Clans (IlClan perhaps?)
My bet is that even if there is an IlClan, they don't get to hold onto Terra for the long hall. Given Alaric Ward's cunning, maybe he decides landing on Terra and holding it briefly gives him the prestige to claim IlClan status, kind of like how he played games with Tharkard (only claiming a continent, just going in to kill or capture Archon Melissa).