Well, OK, this is what I've heard. Folks, this has not been confirmed! If it turns out to be wrong, then it ain't my fault!
1. Eric's description above matches what I've heard. There are two alternatives (2-weapon or archery) and each has 3 stages which the ranger reaches as levels are attained.
2. Beefed up Reflex save, more skill points, lower hit die.
3. A significantly more varied list of class abilities, including things like animal companions, hiding and tracking. Generally more wildernessy.
4. Spells probably much the same.
So, basically, it's looking like a more wilderness-oriented class with a wider range of abilities. The above does make it look like the ranger has been "improved" significantly (which should satisfy those who thought the class was weak), and it certainly seems less front-loaded.
But I'll say it again - this is just rumour, guys! If you get your revised PHBs and you find something different to this insode, then remember that I warned you!