In a recent interview with Glen Mazarra (the executive producer, writer, and showrunner for the walking dead on AMC), Glen Mazarra answered the following question:
Q: Now that we know Michonne and The Governor are making an appearance, is there any other character from the comic you're excited about introducing next?
A: There are a lot of fantastic characters throughout Robert Kirkman's book that we're dying to bring to life. Some will be introduced in this season and some will be introduced in later seasons. It's our intention to bring all those major characters to life.
This answer pretty much flat-out states that we will be getting more comic characters this season.
the rest of the interview can be found here
who do you think will be introduced? how and when? post an answer in the comments below!