I picked up that very first edition back in the day and it rapidly became of one my favorite games in the 1970s. It was wild, it was woolly and it was fun.
Another way that Cosmic Encounter was ahead of its time was with its multiple expansions that added new rules, new pieces and new cards. This started with the Eon editions, but the later Mayfair editions followed the same idea as well. Some of the new rules were well received, others less so. I didn't choose to follow Cosmic Encounter down the expansion route, finding the base game good enough for the amount of play it got from me, but I know that many hardcore fans enjoyed them a lot.
Enough liked those new rules that there was widespread disappointment with the Hasbro/Avalon Hill re-issue, which stripped the game down to something similar to the original Eon version. I got this one, but I have to admit that it did seem to lack some of the charm of the old Eon game in my opinion. The plastic spaceships was a good concept, but the execution was clumsy and overall it seemed like this version was not the final word. Most people who had the Mayfair edition kept using it, but being long out of print made it hard for new players to discover the game.
The new Fantasy Flight edition seems to be an attempt to capture a new audience with handsome components and clean game play while incorporating some of the better ideas from the earlier expansions. I haven't had a chance to play it yet, so I can't definitively say whether or not they succeeded, but it looks promising at first glance. While I don't think there's anything in the game that veteran CE players haven't seen before somewhere, for someone like me who didn't keep up with all the expansions the unfamiliar rules seem well explained and what they add to game play seems clear.
Three mistakes of the Avalon Hill edition were avoided: There are plenty of Aliens, The Game holds five players and the plastic spaceships are easy to use (and look like spaceships).
Fantasy Flight Games is well-known for top-notch game production, so I think there's a good chance this will become the definitive edition of the game. There are expansions planned, so veterans who didn't see their favorite expansion rule still have hope of seeing it, although I suspect that FFG's strategy will be to issue a few, fairly ambitious expansions, in keeping with it practice with games such as Tide of Iron or War of the Ring rather than multiple small expansions like some competitors do.
But I don't think players should feel compelled to follow the expansions. There's an enormous amount of playing potential in the base game and unless your group lays CE an awful lot then I think the base game should be enough.