Kobold,
No I haven't heard about the rokugan in HW.
It seems to me that if you want to run a Lite rule game, with an emphesis on discriptive play. You can use HW with just about any setting.
For a impromtu game I ran HW with a starwars setting. It was great fun. The only problem I have with HW is ranged combat, but with a little tweaking I can be done easily as well.
The Dune game is very nice ( we rode the worm!!), very cinematic.
Im looking forward to the next session ( pentacost next year).
Character generation : Write a story about your character in 100 words, naming the culture you grew up in, Your profession and your faith ( this is the glorantha-character generation). Your DM will assign skills/powers/advantages/disadvantages/abilities from the story and background. And you as a player assign ( together with the DM) your levels in that skill/power/advantage/disadvantage/ability.
Another nice thing is you can use one ability to boost (augment) another. So when escaping from the lair of an enraged bear, you use your Running ability augmented by your Claustrofobia. to leave the cave as fast as possible. To enter the cave you use Courage penalized by Claustrofobia!
If you as a player can describe a plauzible way of using your abilities, you can use abilities in the most creative way.
Combat is set up in such a way that it doesn't matter what kind of conflict your dealing with: So sword and shield combat works the same way as a religious debate or haggling about the price of a Horse. The importance of the event in the story dictates the complicity of the mechanics used. ( not important: simple roll. Pivotal point in the campaign: most detailed resolution system)
HW is really nice! But as I said earlier, Youll have to distill the rules from the book.
There is a simple rule document (pdf) on their website:
www.herowars.com/hw/index.html
btw the artwork on the basic book is, in my humble opinion, VERY BAD!!!!!!!