My next game that I will start making in October will not have a manly rival, but I've seen several request to see one again, so I think there's a very good chance of having one appear sometime next year.
I like to explore different genres and designs, so I don't think I will make a game that is exactly like Summer Sweepers anytime soon. There are a lot of common threads, gameplay elements and guest characters in my projects, and you will definitely continue to see some of what you have enjoyed in Summer Sweepers in anything new that I make!