Carrara will also save 3d models (whether imported into Carrara or created in Carrara) in both 3ds and x formats - exactly right for Wintermute. The dae (Collada) save in any Daz product is still questionable (but may have been fixed in the latest version of Carrara) - but that doesn't affect Wintermute. So, as far as characters and props go, Carrara can and does enable you to make stuff for use in Wintermute.
The big difference - as we were discussing above - is in the treatment of the environment. In Carrara, you can create vast, sweeping landscapes in 3D and populate them with highly detailed 3D models of buildings, people, plants etc. The main problem is that level of detail - game engines can't handle it and still run with anything like practical speed. It's OK if all you're going to do is set up a scene and render it (that's the virtual photograph), but making anything move in real time is a huge problem. Models for game engines need to be made at a lower level of complexity (although there are methods of making them appear more complex than they really are). So, the Wintermute engine (which was originally written as a 2D engine) will not handle your vast, sweeping, 3D landscape - but it will easily handle a 2D representation of it. You make your complex environment, render it in Carrara and import the finished render as a 2D background image into Wintermute. Then you put your low-resolution characters and props in front of that image. Now all the engine has to do is handle the characters and props - the background is a single-plane static object.
Odnorf is quite right in saying that Unity is a good engine - as is DX Studio - but even those engines, designed with 3D games in mind, will slow down if asked to do too much. It isn't too difficult to induce them to drop their frame rates to unacceptable (i.e. visible flicker) levels. And, of course, those two engines are not free if you're thinking of going commercial!!
The question of how far to take your representation of reality in a game is a complicated one. However ... you can create a five-mile wide landscape in Carrara, but would you really expect one of your game characters to walk five miles in real time to cross it? No - so you are going to use scene transitions even in a full-blown 3D engine. The advantage of using a program such as Carrara with Wintermute, then, lies in its ability to allow you to set up a 3D scene once but to create many 2D renders from differing viewpoints with differing lighting. From your single Carrara scene, you could easily manufacture a couple of dozen Wintermute scenes in day and night versions - a whole gamesworth of scenes, in fact.