If I might toss my 2 cents in here, if/when you get around to redoing the home page I recommend you get rid of the activity feed. Very few wikis seem to keep it, probably because they make the homepage look extremely cluttered.
Also, for your logo, if it's going in the top left on the orange background next to the wiki name, I highly recommend using a picture with either the same orange as background, or transparent PNG so it will blend in better. (Or flip it and use a constrasting colour, white isn't bad actually IMO). All of this can be done using GIMP2, which is free.