I'm thinking that the Draenei concept was sort of pulled out of Blizzard's ass without to much forethought. This, in my opinion makes the race both the most difficult as well as the most entertaining to role play. I've since read the lore concerning them and am pretty sure if i didn't go way out of bounds on my character's bio, I at least stretched the hell out of it. For consistancies sake, I'd like to state the knowns and unknowns of the Draenei lore so that we might all get pretty close in our backgrounds.
1) The Draenei come from a place called Argos and back then were called the Eredar. They were corrupted by the Titan Sargeras and turned into demons, save those that followed Valen.
We don't know anything really about the Eredar civilization other than they used a lot of magic. The Draenei of 25,000 years ago (aka Eredar) could have been very different culturally and physically to modern Draenei. We don't know anything about Argos.
2) Valen and his cohort adopted the religion of the Naaru, who where energy beings both wise and benevolent. Whatever this meeting was like is unknown but it is known to be the beginning of the religion that the Draenei follow to this day.
The extent of the Naaru's guidence is unknown. I like to think that the Draenei are a pragmatic and technical people and most of their accomplishments are actually their own merits.
3) Valen flees Argos rather than have his people killed or corrupted by the Sargeras tainted Eredar. This period is described as going to one planet to the next staying one step ahead of the Titan's legions. How many worlds is not said only that it was many. It could be that most of Draenei history is this period. It is likely that generations of Draenei grew and died mostly on ships going from one place to the next. If anything could have bred the communal and determined virtues possessed by the Draenei it was probably this era of urgent nomadicism.
We aren't told where they went exactly. We aren't told how many their were. It is likely the numbers weren't that big. It is also likely that this period forced the Draenei to perfect Nether travel and by extention their 'crystal-based-technology.'
4) The last stop in the Draenei exodus is Draenor. Named Draenor wich means 'refuge' for Draenei which means 'Exile.' Thus Valen saw fit to call this planet a refuge. Which probably means he meant to stay this time. It is mentioned in the lore that the Draenei dumbed their magic down a bit as a way to hide from the legion. This is important because the legion does in fact find Draenor. Was it because some Draenei mages didn't keep sufficiently Dumb? Was it just bad luck? Was it betrayal? Was it that the Draenei were still plying the Cosmos and got themselves found out? Who knows?
The Draenei on Draenor lived for many generations alongside the orcs. Draenor is also the birthplace of the orcish race. That cool coincidence gives us some idea what Draenor was like. Draenei civilization persisted on Draenor for a good long time. It is likely that kids on Draenor thought about Argos as sort of a dim fantasy land and tragic creation story it would have been so old by this period.
5) Sargeras finds Draenor. The Titan corrupts the orcs as he had the Eredar and unleashes them on the Draenei. This is the was the Draenei eventually loose. It is described as a big world-breaking war. Seems like it would have been Draenei technology versus Orcish ferocity. However skilled and clever the Draenei were, their civilization ends here. Whats left is Zangermarsh in an unwrecked portion of Outland (I.E. Post apocolyptic Draenor). This remenant is the closest thing that any of the Azeroth bound Draenei could call home. Apparently the Blood elves had joined in the war during its closing months particularly to plunder Draenei magical knowledge. The Exodar fell into Blood Elf hands for a time. The Draenei, still under Valen's leadership (Appaently this guy has always been in charge), had to steal the ship back but not before the blood elves had sabotaged it. The sabotage is the reason it crashed.
That's pretty much it. So as I read it. Most young Draenei were born during or after the orcish war or in Zangermarsh some time later. This doesn't say what the Draenei are doing on other worlds or why they seem so happy to ply around the nether. I would guess that Draenei civilization continued to some degree but isn't nearly as expansive as the other races.
So could the lore afficiados add anything to this?