Are there ever going to be more badges added, and possible to get?
Probably. They added two new ones just this week.
I suppose if I'm going to post an answer at all, I should explain more. The team can add badges at will. They often add badges when new major features are introduced, to get people to use them or at least be aware of them.
Other times, new badges' criteria are suggested by or at least inspired by the community. You can suggest your own badges here on MSO by posting new questions explaining your desired criteria with the tag badge-request. Looking through old questions with that tag is a good way to see what does/doesn't make a good request.
You can see a partial history of new badges being added at the list of recent SE feature changes.
Right in the recent past new badges have been added: Excavator has been added about one day ago, and Proofreader was recently added.
If by "possible to get" you mean possible to get for users with a reputation of, e.g., 500, then I think there is few that is not already covered by existing badges.
Consider also that a badge is created to promote a positive behavior on an SE site; they are not added for the sake of adding them. For example, you could think of adding a badge for who commented 200 times, but as this is not the behavior an SE site wants to promote, such badge will not be added.