According to the website, future event themes include Steampunk music, and making Steampunk related 'gubbins' (for want of a better word) among other things.
The museum also has a nice steam railway, and some very impressive steam engines, including the worlds largest working beam engine.
Even better, you only have to pay the entry price once, and it gets you into the museum for the rest of the year.
I'm going dressed up in my finery with a couple of friends. Look forward to seeing you there!
(Note, I don't actually work for the museum, this just looks like a mighty awesome series of events, in a very cool place).