Wow! This seems like sooooo much fun!
I would definetely love to have an Alice in Wonderland wedding!
I am a huge fan of everything DIY.. so here's some suggestions i thought of, sorry if they are repetitive (i didn't read the whole thread lol)
First favors:
I recommend doing a little chinese-style take-out box that either has "eat me" on the side or somewhere on yr candy/cookie/whatever you are giving away. I think a small cookie would be nice, with "eat me" iced on there. I have a great recipe to make icing that hardens and looks shiny, like a cookie you buy from the store with the super shiny, hard icing.
On the inside you could also include a small poem, or phrase from the book/movie.
here's an example of the box from another post on craftster:

and this is what they had inside:

Another idea, i've been making favor/gift boxes for my web site on etsy. Here's the website I used that has a pdf template. I clicked on the "petal favor box".. It will be really simple to change the flower to a heart, if you like that better.
http://vintageglamblog.com/2009/01/freebie-fridays-favor-box-templates/decoration:
I like the idea of the mixed and matched china; for the centerpiece you should have a large teapot filled with roses and then set the teacups around on the table.
They large chess pieces sounded like a great idea! I would definetely do those! I'm sorry i can't think of anything better to carve them out of, other than styrofoam.
If you are planning on an outdoor wedding, assuming you are not using pews I thought it would be really interesting to do a small, fake chess board and use some of the chairs as the pieces. I've only been to a few weddings, but the classic example of the wedding is everyone is facing the couple at the front and there are chairs on both sides of the aisle.. Have the immediate family from both sides sit in the "chessboard" chairs and the aisle be red carpet. The main colours of Alice in Wonderland are black, white, and red... It seems weird as i'm describing it lol, but it looks cool in my head.
And a crappy paint drawing of it lol:

I also read that someone recommended paper lanterns.. I like small origami ballon lights, if you are interested in those, I have a picture.. They are really cute and do put out some light.. But, i recommend using the LED christmas light, because they don't heat up like the regular lights do... and get the white wire, it looks prettier.
I have instructions to make them if interested!
Here's some I've made:

OH! Another brainstorm just hit me! For the lanterns or ballon lights.. which ever you choose.. Pick white ones and paint small-ish hearts on them sparatically.
Attire:
I thought it would be cute to have the little girl dress as Alice.. Since this will be a themed wedding, you are obviously the bride, but you need an Alice there.. The flower girl! That would be adorable!
You could ask your guests to wear a certain coulour perhaps? If you don't want people to be in costume it would be cute to possible give each guest a heart to pin on their clothing as they arrive? Or not? lol
Thats all I have for right now. I'm rather sleepy! But i'll keep brainstorming for you!