I know a few have come and gone, but as I'm not plugged in to what else is out there at the moment, I really can't help. Basically, I'm reply to bump your question. ;)
Polyhedron is not being published by anyone anymore? How very unfortunate.
How about a Polyhedron length (20-30 pages) bi-monthly PDF magazine from Paizo? Annual subscription price $9...I'd buy that. $1.50 per issue. D20 modern and all that good stuff that was in Polyhedron before.
I hardly ever used any Polyhedron material, but it was fun to read and gave me good ideas for my game. That WWII d20 system for soldiers and stuff was one of my recent favorites.
You can always find stuff online. i think the website is Agyrus or soemthing like that. they have a complete world of D&D D20 material. its not oriental but im not sure if they have options for it its been awhile since i've seen it. i know its in one of the Dungeon magazines for their ultimate D&D table.
My favorite D&D/RPG sites are:
http://www.d20zines.com/
This is fairly new to me, but it's interesting stuff.
http://www.roleplayingtips.com
You Need This Site(tm). Tips and ideas GALORE.
http://www.tomeoftrouble.com
Justin Gasal happily provides tidbits of information on feats, items, prestige classes, spells and more. Each email newsletter is centered around a theme - for example, sometimes he does Traits, another time he focuses on constructs and so on. He only archives a few of his issues at a time, so there's a lot of them that aren't online. I have metric buttloads of his back issues in my inbox.
http://www.treasuretables.org
Lots of GM/DMs jawing about theory, tips, and ideas.
Yahoo Group - GMMastery
Not just for d20/D&D.