Isometric view with prerendered graphics is very cool. I like this (you love this), and i'm a big fun of isometric view and tiles. But tiles and perendered graphics it's a hard work for artist if you want recieve after release the game - good and fine picture like Fallout, Arcanum, Planescape torments, Temple of Elemental Evil or etс.
You must remember three things:
Firstly. Original resolution of many old games 640x480 or 800x600, today people want looks game with resolution a minimum 1280x1024. What i want to say? Artists of enXile must have a lot of work with graphic content.
In earlier games developers have a limit in resolution. It was bad, but it was the economy. Today developers have no economy - gamers love a pretty picture.
I named its - problem ONE (time of development)
Secondly. 2D content have no way to customization level. Even you used many object tiles. Tile and sprite objects have no rotation opportunity. And have no reuse in other locations (if backgrounds maked like Planscape Torment - where developer make complete and full prerender in all locations). You mast remember - if you make unique background like a big-damn-art you mast ready for surprises. Somethimes somebady knock in your door and be say:
Big Boss: John... in 283-location, background number 308 we want move wooden box.
John answer: ^$^($@... i love you guys! I thought that I would spend weekends with family!
Thirdly. Brian Fargo & Co have only ~1.5 year to development of this game. They must find a way to make the game fast. There are many ways. For example, a combined graphic. 3D character models (not to make thousands of sprites of NPC and characters) and 2D graphic for location, worldmap & etc.
If someone suddenly asks my opinion. I answer:
If I did game, it would have chosen the following provisions:
- 3D models for Characters
- 3D-objects and "3D-tiles" for level design
- 2D graphics for worldmap, menus, inerfaces and additional graphic content
What i mean talking about "3D-sprites"?
3D-objects like that placed on 3D-level, or maybe on 2D-level.

At any time, you can rotate an object (if this object model), a grid mash it, put on the ground, "dip" in the sand. And it will always be one model. It's - economy. Economy of time developers. Put model on level - and forget.
If developer need 2D sprite - He must render this model in different angles, and after this build giant library with this sprites. You working with Fallout Tactics Engine? (i mean FT:BOS editor). It's cool. But very hard for designer. thousands sprites, problem with a levels, problem with sorting tiles. This work "eat" lot of time.
It'a a problem of all tile engines, you have many objects - ready for lot of sprites.
Now think about it. This is a vintage drink machine. ONE machine. And if you need five or ten? But what if objects in the game 200-400? You make a render for each sprite will for every possible angle? 12 sprites on each object?
Don't answer "Yes" - You have no idea how serious problem you have in future after this decision.
What about camera? If you want isometric - game camera can be changed. Change the camera from Perspective (with a specific FOV) to the Ortographic mode. Disable zoom. Аnd you'll get the same isometry! Classic isometry.
But - with dynamic light sources, with some technologies, honest shadows, etc.
Do not be afraid of a 3D graphics. All her problems because many developers do not know how to "cook" 3D. Look at this picture. This is a 3D, without aliasing filtering and other graphic fint. It looks good. Because it's done as needed, not as others do.
"In development" screen:

Full resolution: http://lionwoodblog.com/pictures/hi/serenity.jpg
(3D scene have no shadows, have only one dynamic light, it's not a fake - real time model. A have no time to finish this scene, because (laugh) i paint Wasteland 2 fan-arts)
http://wasteland.inxile-entertainment.com/forum/viewtopic.php?f=18&t=314
If you add to this scene beautiful earth, sand, a bunch of rusty pieces of iron, automobiles - would be great. And this bar can be used in another state. In a thousand kilometers out of here. Repainted textures, removing iron and sand, adding rocks and other objects. And mirracle - another bar.
But if you draw it in 2D - it will be the same everywhere in game world.
Draw by artists hands all what you look in the world - cool. Funny. Great. But the guys of Brian Fargo is not have 3 or 5 years out to make this game a dream with unreal fully painted and unique graphics. Even if Fargo hire lot of tallented artist. This task for big-damn companies or for developers have no time limits.
Fargo have limit in time and have limit in crew.
P.S.
I also hate 3D and I hate to do it (just kidding). I really love most of all 2D graphics. But I am well aware of the possibilities of 3D graphics. The main thing - to skillfully use tools.
P.P.S.
The most important thing guys - it's not graphic. Game-play is a queen, god and the lord of any game. The graphics, the code - is vassals, without the right to vote.
Therefore, it does not matter, isometry, 2D, 3D, first person mode - all of is vanity of vanities. The MAIN - game itself.
Why do you love the old games? For the graphics? For the shaders? For 3D? (smile)




