Mongoose traveller still retains it as an optional rule to chargen. I like their new verson better though. Sometimes the crippling injuries will make you wish for death instead. I've had several force me to forget a otherwise very promising character. My very experienced marine got hit by one that basically caused him to become little more than a quadriplegic. All those awesome weapon skills and armor can't really do much without the ability to carry anything.
Classic Traveller and Mongoose Traveller use pretty much the same setting. The only differences there are some of the mechanics are slightly more forgiving, or balanced, whichever you'd prefer to call it, in Mongoose. Classic is good, and there is a TON of stuff available for it, but it's VERY VERY easy to just use classic stuff for a mongoose game, there's very little work to converting it over and I haven't had anything come up that either didn't convert easily, or I couldn't just fudge a bit to get to work.
The best way to describe traveller, is to tell someone to watch Firefly. Granted, characters generally won't have as entertaining quips as the written actors in firefly, but the theme is very similar.
On the other hand, I find it almost infinitely moddable within reason. I wouldn't throw in too much magic(although the psion rules give you some ability there) but as an example, I've been wanting to run a war in the setting, giving each character maybe a small squad of helpers and giving them various missions throughout a campaign.
Anyway, yeah, I want to play traveller badly, but the few games I've tried to play haven't really gone anywhere.