OK, here is some info I have on Kashyyyk and the events that happen there. It comes from a few different sources - some known, others not. Some of you guys already know about this stuff, and to others some of this info is already known, but that's not gonna stop me from rehashing some old stuff

So anyway here is what I know for anyone who is interested:
The why's and how's are more difficult to answer eg.
why is Yoda on Kashyyyk? Is he there for a reason for this other than leading clones against the separatists?
what is it about this planet that is so important?
Going by what
EP has already said, GL has really tried to distance this planet from Endor by giving the landscape and vistas a different feel - massive lakes, gargantuan sprawling trees, organic-type weaponry and machinery, and a technologically enhanced species aka the Wookies. Besides
The Duel this is one sequence I'm really looking forward to seeing, for a few reasons too.
From what I hear, the
Battle of Kashyyyk is the catalyst as far as truly ending the Clone Wars. The clones are doing a good job of decimating the droid forces with the help of the wookies. It's about this time when Sidious orders the clones to turn on the Jedi and anyone else nearby. Yoda creates confusion for some neatrby clones by turning into the befuddled old alien we see in ESB. This lasts long enough for him to waste the resistance around him, and it's here I think that Chewie makes his appearance by grabbing the Jedi Master and high-tailing it through the trees at break-neck speed. In order to get to the Wookie city/spaceport they must journey through the forest and away from the clonetroopers, who are now ordered to blast anything on sight. This is where things get hazy as far understanding motives goes. Chewie shows Yoda the remains of an old abandoned Jedi temple/outpost regarded by Chewie as a sacred place. Yoda begins to explore the ruins and here he comes across *something of importance*. I've been told it's a Sith hologram. What it's of I'm unsure, but his may be the reason why Yoda is so keen to get back to Coruscant? Did Yoda know this temple was on Kashyyyk? Is this why he was on kashyyyk in the first place? hmm dunno... Anyways they scoot from there and finally arrive at the spaceport, which byall accounts looks friggin' amazing perched up very high in the treetops. "Elevators" are used to get up to the canopy and Chewie gets Yoda to a transport straight away. This is the last we see of Chewie until ANH. Yoda's destination is Coruscant where he meets up with Obi-Wan and where they discover they have been rissoled by the Sith.
From here it's all bad, real bad.
SI