Maccus asked if we would see any of the Alien races present in the Traveller universe at all in this game.
To really answer that we need to better establish the location of our generated sector in regards to the Imperium and universe as a whole. The different races border the Imperium in various places, and while solitary members or small communities of each race likely exist in pockets or roam about the Imperium, mostly the alien races have their own space and own governance elsewhere. Traveller is more Star Trek than Star Wars in that regard, if that makes any sense. The Imperium has not conquered all of known space and all these various races been absorbed by it. Like Klingons, Romulans, Cardassians, etc. they've each got their own dominions and borders and for the most part they stick to them.
The Aslan are basically space lions that have their own space but a few of their systems are actually under Imperial rule.
The Vargr are space wolves that have their own space and there's no sharing of systems at all. In fact they're kind of regarded as all-around pirates and marauders due to some wars and the fact that THEY LIKE TO PIRATE AND GO MARUADING.
The Darrians are basically space elves. They have their own space which isn't too far from the Aslan territories but is also independant of the Imperium like the Vargr. They're also not regarded too greatly because of their advanced technology and the fact that they basically hold the Imperium at bay from conquering their shit by merit of a super advanced doomsday weapon only they possess.
Finally the Zhodani are a human offshoot that are basically a race of psionic monks. Their major territorial holdings are off by themselves, but they do have a few systems in bumfuck nowhere that they share with the Vargr...oddly enough.
There are a few more major races that just aren't detailed at all in the current edition (The Droyne, Hivers, and K'Kree) and a multitude of minor races that populate the galaxy.
Th gist of all this is that, while the sector itself is a Human-populated Imperium sector, there's potential for us to be close by some other races and have them pop up more frequently in a limited fashion.
There is another option to scrap our entire sector and move the campaign to the Spinward Marches:
http://wiki.travellerrpg.com/Spinward_Marches_Sector
Which is kind of the hot-bed for all that crazy alium goodness and the closest thing to a primary setting Traveller has. Kind of like how Seattle is to Shadowrun, the Spinward Marches is to Traveller.