This is an ambitious feature request, but one I believe we'll have to do (or some variant) at some point in the future, as we simply don't have enough room in the single-pane new game menu for a future 12 players, more options, etc. It's pretty limited as it is now. But a picture's worth a thousand words, so I put some thought into this proposal and came up with the following concept:
Firstly, we start by having the user pick the techtree. By having this an entirely separate screen, we don't pressure the user with too many options at once, and give space for us to add a short description, which will be found on each pane. We display a list of the factions inside the techtree to aid in choosing, not to mention those ambiguous cases ("ugh, what techtree did I put the dwarves in?).
There's also the ability to add a description to the techtree. This is done using the already existant, but unused, name element in the faction XML. Presumably, however, it will reference a language file key, so that we can have the description translated (for legacy reasons, if not found in the language file, fall back to the english language file. If not there either, display the value as is).
Finally, having a separate techtree also takes into aspect the potential future possibility of restrictions based on the techtree (eg, if annex had a GAE version, it might want to restrict itself to the specialty tilesets and maps that are bundled with it). Of course, such a feature doesn't exist anyway, and shouldn't be worried about.
Next, we have the player choose the map. The reason this is done before choosing the factions and players is because the map determines the number of players allowed. This ability to have a map preview is one of the biggest reasons for this proposal: there's a lot of maps. I got about 80 maps myself, all distributed with Apocalyptic Dawn. I can't claim to understand the technicals behind how a map preview would work. If a live snapshot (as in, render a single frame image of the whole map, then display it as a static image) can be rendered in a practical amount of time (under three seconds), that would be utterly godly (the tileset could be taken into aspect). If not, check for an image (TGA, BMP, PNG, or JPG) in the maps folder with the same name as the map. If none is found, display "no preview", like
this alternative version here. I have images for nearly ever map, and could supply them easily. If live rendering is possible, it may be desirable to cache the images, preventing that wait time from having to be repeated.
The other awesome thing about the extra space we have is that we can display the title, author, and description, which are already stored in the map file (those values shown there are the actual values in the Wadi Nefud). If title is empty, display the name of the map.
And the final screen, naturally, lets use choose the players, their faction, their team, and their colour. This is basically the same as the player selection, but as shown in the image, can hold up to 12 players (these are 800x600 images, which should be the minimum resolution to run GAE).
And that's not necessarily everything. While I don't propose we add anything else yet, these panes could be expanded to also have another button on the last screen for an "advanced options" pane, which could give options for more advanced per-game settings, such as the end game action, observers, etc.
It'd also be rather useful to use our tooltips feature on this menu. So hovering over the faction drop down box could offer a short description of what a faction is. Hovering over the size attribute on a map could explain what the size means (as well as mention what size is a medium sized map, small, etc). That function is optional, and could also be applied to our current menu. The "x" at the top right corner of the window is supposed to "close" the new game menu, taking you back to the main menu, but without a tooltip, the only way to know that is to click it.
[small]Note: again, these are just images, I don't have the skill (yet) for anything like this. Just some mean image editing skills.[/small]