I would do a few things.
1. Pre-Ren Server. Possibley just Pre-Pub 16.
2. Close three or four server's down. Offer the player's there some incentive and all the transfers they'd need to relocate any and all characters and items, even throw in a free month or two for them and open up previously unplacable for no apparent reason locations for housing.
3. A revamp of factions. Everything. The factions themselves, the point system, the sigil system, all of it. All current bases would be rebuilt into actual Fortresses. Town's would be reconstructed to appear as though they've been built around the fortresses...
It would start as an event where some random ultimaesque bad guys gather all the Blackrock that miner's have been digging up since the Last few events, and they would cast Armageddon. Being stopped at the very end of course but not soon enough to cause complete devastation to Fel. I'd remove the random ass tombstones all over and replace them with more gruesome post-nearapocalyptic things. The overworld animal spawn would become twisted and evil, the trees scorched or just knocked over, old shrines would be destroyed and towns demolished, corpses all over. This is when the factions realize this is the right time to mobilize and build up bigger and more powerful than before. They build their new empires and the battles to rebuild the world in their image commence.
Clearing away the rubble would be the first thing. All guard zones in fel aside from the moongates would be removed, and players would need to clear away rubble searching for survivors and the dead. Players would get neat incentives to do so, such as new deco, new arties for doing this, which would be later introduced elsewhere, this would merely give them the first shot at them, as a reward for much easier tasks then they would be later on, which I have some neat ideas on, such as weapons that begin weak but grow more powerful (to a point mind you) through use (such as a weapon that collects Lich souls/black blood/whatever they have, and eventually becomes a really nice undead slayer, or PvP ones that collect murderer or innocent souls and such). Then after that materials would need to be collected for rebuild, and these would offer a new set of one time around items, more deco, a few neat suit sets, shirts that say "I survived Armageddon and all I got was this lousy fancy shirt/doublet/tunic and various other funny, cool etc. items.
Then as this goes on, new fortresses are built for the factions, HUGE fortresses, complete with everything a fortress might have (I havent spent much time in any so I'll leave that up to people who would be wiser), and NPC guards patrolling inside and around the surrounding city (which I bring up next), no hiding possible inside a faction Fortress except for the faction that owns said fortress for ambush purposes, hell i mean it is THEIR city/fortress. Have the guards work on a line of sight attack mode (they would attack if they "see" you and chase you until you have actually lost them, not just when you turn a corner), have them yell for help and if another guard is in the vicinity they will come to aid. Send a warning out to factioners when their base is under seige (assuming a guard has spotted an enemy).
Cities built intelligently AROUND the new fortresses, with full sets of NPC's that might be AROUND a growing army. IE: Blacksmiths, Leather workers, Provisioners, Ship builders, map makers, tailors, fletchers, mages, alchemists etc. Outside the city there would be farms, both livestock and vegetation (people have to eat, even if we're just pretending they eat).
Faction armor would no longer have rank requirements. Faction rank would instead, give you reduced prices on all the goods in the surrounding town, perhaps even special high rank NPCs with special items available only for your faction (perhaps unique to factions artifacts that are more faction specific IE: hued for your faction, or maybe special ingredients for crafting ML items and Imbueing) and rank would be a combination of faction kills, sigil grabs/assists, succesful trap damage and time spent in the faction. The only way to lose faction points would be to kill a member of your own faction, or ignore a "call to arms" (an enemy factioner being "spotted" in your base) which leads to the loss of sigils (such as for every sigil stolen, while you're not in your base defending you would lose a point, assuming you're online, for every friendly faction kill incident a loss of 5 points).
And I've got a few other ideas bumbling around in my head but honestly I've already written a novel here... sooo... yea. That's the gist of it.
EDIT: I forgot to mention, the shrines of course would be rebuilt, something a little more special without being grandiose and pompous, and there would be the unveiling of a new dungeon built by an ancient civilization that became consumed by evil and was ultimately buried until the world shook and unearthed it's entrance. I'd go more in depth on these but I said above, I've typed enough.
