I've been looking around for awhile now and have not seen much on this topic. Its all either super realistic RP, medieval fantasy, or space. Each to his own, of course, but I was disappointing not to see any fantastical Diesel/Steampunk like NRPs. So what I propose is a custom world where the setting will be very similar to the early to mid 1940s. Something like Valkyria Chronicles, Skycrawlers, Sky Captain and the World of Tomorrow, that sort of thing. I would like it to focus on having fun, so as part of the rules, the game will have its crazy giant improbable tanks or flying contraptions that can be overpowered! BUT! This is because they SHOULD be allowed to be defeated through some impossible odds or whatever! I think the Roleplayer Guild so far has a very trustworthy community, so I would trust that people wouldn't just abuse that freedom.
Anyway, who else is interested in this sort of thing? Some over the top, fantasy tech filled, simple, fun, NRP? More details about the world, map, ect. will come as more people show interest.
Oh and be warned! This is my first time ever GMing.... anything really, so I appreciate any tips or pointers to help the NRP grow and thrive.