First of all, 2238 uses the Fallout 1 and 2 worldmap merged to one big. Beside this, forget every quest and stuff you remember from the original games-- 2238 is set 77 years after Fallout 1 and 3 before Fallout 2, we have a different scenario. Quest wise, the 2238 server has not much to offer yet because we are still working to get all basics done. At the moment there are the factions, brahmin trading, slaving, etc. etc.
We use the same Graphics as Fallout 1 and 2, also we are creating new scenery graphics, etc. etc. We have some new critter graphics too but nothing that can be used for players. So, yes, all people in metal armor will look exactly the same.
You can only play humans because humans are the only critter-types who offer all animations. It could be also possible to add super mutants and ghouls and disable for the player that he can use weapon x and y but even then... trust me, it is damn annoying if you cannot run and super mutants and ghouls cannot run. In the beginning it is still fun, but after one or two days it just sucks because you are very slow.
We (the 2238 devs) are mostly roleplayers. We don't like endless stupid grinding and so we try to avoid this and give other things you can do. For this we are working on a big crafting system with professions and so on. It is already in game and will be updated from time to time. Beside this, we have the other stuff named above... brahmin trading, slaving, something that is called "Town Control", etc.
Beside this, we plan to introduce special events every now and then. They will be lead by game master and offer more or less unique quests. We will se how this will work out.
Yes, 2238 started approx 8 months ago as "Faction Mod" that aimed to allow players to found factions and manage their members easier etc. You don't need a faction- it is still possible to move around alone. If you don't want to be in a faction but also don't want to run around alone, you can team up with other players and roam around. Beside this.. travelling with other players in a group is always saver... we have no non-pvp zones. Everybody can kill everybody everytime on every place. Some locations are saver because of police forces and so on but you can still die everywhere and loose everything.
The open beta starts tomorrow, yes. Time is most likely from 15. to 16.. but don't ask for exact GMT time... I have no clue right now. (I would say GMT+4, not sure tho')