I'm not so much worried about megagames.com really - it's too big and massive of a site to just up and vanish... (though a backup isn't a bad idea)
as for Xeal and DeXT (can't speak for Darkfalz here), their sites were nothing more than free personal homepages... and surely they care enough to make sure their stuff stays online - it was the webspace providers who took the pages down because of changes in their service/billing, something like that. I must assume that Xeal and DeXT just haven't realized yet that their pages are gone... Maybe someone knows how/where to contact them and let them know?