It'd be nice to see a multiplayer Surveyor option; enabling more than one person to work on a large project at the same time. I'm doubtful that will be included though.
That said, I'd rather NV3 made some more complete content packs, or perhaps outsourcing to get a route, stock, and scenarios that are of a 2010 standard. Rather than just a single loco and carriages, a route with nice high res textures and such also. And fix 2010's bugs. I'd love to be able to purchase an official Trainz product that actually looks and feels modern. The disorganised mess we have now feels like we're still in 2006.
I have a feeling multiplayer will just create a big new world of bugs more than anything else.
I can imagine the surveyor working together idea would be difficult because of saving, would both people save it and to their own computer or what?