We've all been talking about shields and the Warp 7 engine, and those are likely the two biggest items coming down the pipeline for us, but I wanted to take a look at the technology sheet and see what else might be coming for us.
Hull: We haven't seen a hull upgrade yet, so wouldn't be shocked to see a new hull material in the next few designs.
Tactical: We've just upgraded to photonics and pulsed phase cannons, so I think true photons and phasers are a generation or so off still. Shields seem like the next big upgrade, and we know to expect that.
Sublight: Probably not right away, but it seems likely we'll have an update to the impulse systems in the next few classes.
Warp: I expect the Warp 7 engine to come with a pretty total overhaul of the equipment we use at warp, not just the engine. I'm betting a new set of nacelle coils and a new deflector are going to pop up. I also wouldn't be totally surprised to see the new deflector and shields connected somehow, though they might not be.
Endurance: I don't think we'll see anything to replace the antimatter pods particularly soon.
Computers: I think a computer upgrade is unlikely in the immediate future, but it is a possibility for certain.
Transport: So far, we haven't built anything large enough for an actual shuttle, it's all been shuttle pods. I don't see this changing very soon, honestly. Maybe with a new heavy explorer. We haven't heard much about transporters, but the change from "people in emergency situations only" to "standard transport method" should be coming soon, and might require a new fit.
In short, I think there's a big wave of prototypes headed our way, and I suspect most of them are going to end up getting trialed on the same ship design, which probably should be the heavy explorer, since it'll be eating industry anyways. I would suspect no new weapons, but a total overhaul of the warp system is going to be a pretty intensive change to make to our designs. If we don't prototype everything at once, I'm hoping we can do some of the prototypes, maybe for shields, as a refit to the Enterprise-class, in order to be able to put everything together on the newer explorer. The last thing I want is to build a new explorer with either shields or the warp 7 engine, instead of both.