I'm feeling your pain. I recently returned, too, and am blogging about that and other things. You left a lot longer ago than I did, though, and it must be even stranger.
I have seen a lot of people still wearing system clothes. I don't know about the methods for making the skins but I do know the quality of skins has greatly improved since the last time I was here when orange seemed to be the rage. Since 2007? Skins will be totally different in looks, if not methods.
As for mesh, I'm not convinced it is such a great thing. At least with glitch pants I could sit down in a skirt without it poofing up and making me invisible. https://sla2z.wordpress.com/2014/06/10/alphas-add-avatars-and-appliers-oh-my/