2 dimensions or 3 dimension

there is little way to make a hexgrid into a 3d space.

Unless you have a nongrid universe a la Sword of the Stars, I doubt a 3d map would be applicable. Or even desirable.

I don't see how a 3d map could work.  It would be impossibly cluttered and hard to navigate.

I don't know for sure, but let me put it this way. It's 99.99% sure they will go for a 2D  map. 0.01% chance maximum they will do a 3D map. That would be just to look cool, and not caring about easy access to information and epic gameplay. Extremely unlikely Stardock would be that crazy. So reallly no point in speculating about this. 

And besides, our galaxy (the milky way) is almost flat anyway. Well, it does have some depth, but it is such a small proportion of its diameter that I don't see how it would be all that worth while anyway. And since the reason for its near flatness is quite scientific, making GalCiv's galaxy a spheroid would just be too unrealistic for me.

I'm trying to remember which older game had 3 dimensional stars.  In fact, while the galactic disk is indeed pancake shaped, it does have a fair amount of 'girth' along that disk.  which is why when you look in the sky, you see stars in all directions, not just say along the equator.  Of course, if you are away from light pollution, you can also make out the Milky Way as a band crossing the sky.

I just remembered, Ascendency has a 3d star grid, with set warp lines/links.  You can rotate the star grid in 3 dimensions to get a better view of your own empire, etc.  This could get tricky sometimes, if a star was showing in front of/behind a link, hence 'fooling' you into thinking it was connected to that link when in fact it was some distance away from that path between two systems.

That being said, while it would be cool, it doesn't really add a whole lot to gameplay, especially where fleets don't form 'battle lines' in GalCiv due to the vastness involved.  The 2D star plane adds enough elements for now, and I'd rather see the designers focusing on other things, like new cool techs and such.

If we had a LOT more fleets, then you could spread them out to protect all of your borders, but essentially we move fleets to intercept, or leave them near a planet to defend, but open space is too vast to make a 'long defensive line' truly practical from all directions, unless you have only one or a couple of star systems colonized.

As for how you make a 'hex grid' 3d, it is possible, when you think in terms of triangles instead of hexes.  Essentially, the next 'layer' up is offset from the original grid by 'half a hex', and so on.  A better way to visualize this is to think of the hex grid as points layed out in a hexagonal pattern, not physical six sided shapes.  So from one point, you have six points you can move to  Similarly, From that central point you will have a number of points upwards and downwards you can move to.  I'm visualizing 3 up, 3 down, so you have 12 options for movment.

Really though, if you are going 3d, ya might as well lose the grid, and just go with distances.  Of course, how you'd visualize an object's orientation on the Z plane is an interesting problem in of itself.

I don't understand his comment of a flat galaxy, just because spiral galaxies are disc shaped, doesn't mean flat, thanks tjashen for pointing out the obvious, also spiral galaxies aren't the only type of galaxy out there.

I wasn't thinking it was possible to create a working 3D space environment but, if they could create a working model that was easily managed it would be more realistic and add extra challenge to the game play environment.  The only way I could see this ever working and still make it easy to manage and see everything without becoming overwelming and hard to follow would be a 3D (holographic) monitor, which just isn't feasible at this point, even if someone could afford the hardware, it would just be a small amount...

With that being said it would still be cool if there was a way to do it...

I'm sure the game will be great,  Stardock take my $100 please... (okay wait a week till I have it :P)