Well, the current plan at my table is that the GM is going to take a break, and I'm going to run a game of 4E for a while to give him time to reflect. At that time, we'll decide whether to convert or whatever.
I will probably be using material from the Last Point of Light stuff that's been getting kicked around rpg.net. For those of you not familiar, it's as follows: The PCs are from a small, isolated village. Monster attacks are getting worse, and the baron and his soldiers set out to fight in some war several years ago, and never returned. It's been probably a decade and a half since proper tribute was paid to the king, the roads have been far too dangerous for taxpayers since then.
The merchants haven't come either, and the lack of things from the outside is beginning to sting. The baron's 'castle' had to be boarded up, after the last time Kobolds took up residence in it. Things are getting desperate, and the PCs, after a couple little scenarios to introduce themselves and let themselves get to feeling badass, are appointed to take several years worth of taxes, get to the Kingdom (it's estimated to be down a road on the other side of the mountain pass...in any case, they should be able to find their way eventually) and get help and supplies.
Slowly, over the course of exploration of ruined cities, scattered journals, wrecked villages and unburied dead, the PCs discover the truth. The fall of all mankind happened, and nobody thought to tell them. The monsters took over, and civilization gradually fell. As nearly as they can tell, they, and their village, is the last.
