Nice info and answers in this thread.
That said - it's quite a big question you give us Carlos :)
"What i want to know what can i do with a clearpass with ARuba and what i can do with clearpass but with NON aruba equipments"
Perhaps the first question you want to ask and answer yourself is:
* What do we want to use ClearPass for?
* How granulated authentication/authorization do we want?
* Which modules do we want to use?
I've had several customers that have no problem seeing the Guest part, and then a little more convincing needed for the next step which is BYOD. Here they usually don't want to go further than "if company owned PC then assign allowall roles/business vlan, non-company owned = byod-role/guest vlan".
This you can accomplish with anything that supports Radius.