HIdeas:
Plugins: Link to specifically-helpful-for-2D plugins, like D3D, AdvancedSPRITES, and Aaron Miller's Advanced 2D.
2D Techniques: For example, tiling, sprite pasting, viewports, etc.
Tutorial/Theory Discussion: Platformers, Top-Down Racers, Puzzle games, Retro games, etc.
Sprite/HUD/whatever tutorials.
Sprite/HUD/whatever sharing/critique thread. Debate the hell out of that sprite, something good will come of it. I don't mean to say let's all start acting like dicks, but you know.
2D Competitions: Games, Art, whatever.
Start off with a "whoa cash prize" competition (something in the style of the DBP Christmas challenge a year or so back) and have it plugged in the Newsletter.
Also introduce a new section in the Newsletter about 2D, "From the Board", whatever. Meanwhile, begin a few "main" threads along the lines of those suggested above, and get as much content into the first post as possible.
Round up a bunch of like-minded (like DSArchy, Picone, Deathead, and Mortus to name the most instantly notable, plus other "big names" who you think might want to involve themselves) to see what they come up with in the first few replies, maybe start off some more threads.
Pop "2D OR DEATH" or something in your sig with a link. You're laughing come March.
In other words, one big push may reinvigorate all sorts of interest.
I've no idea how you'd go about most of that, by the way.
D:
Space Game - DarkEye - Concentricious - Probsequest - Puyo
seek out the chalky dust of the love salmon