Is there a path in order to get upgrade from 2.9 version to 3.0rc ?
Im using and Intel Box with 2.9.48 routeros, 3 interfaces, several hotspot servers, several user profiles, traffic shaping with simple queues, some firewall rules, virtual server on hotspot interface, internal database for hotspot users, etc.

Are features on both version compatibles ?
How can i run a smoothly upgrade ?

Thanks in advance.

Upload the new packages via FTP, log into webbox and click Upgrade.

I've had 2.9.46 on an AMD K8 machine which I upgraded to RC5, works perfectly fine.
Also an RB532A that had 2.6.38 on, upgraded that to RC6, works perfectly fine.

Thanks for the advice krigevr.

It seems to be the same procedure as upgrading in 2.9.x versions.

Is there any differences in features between 2.9.x and 3.0.rcx versions ?

My settings on version 2.9.x still working after upgrading to 3.0.rcx ?

Thanks again.

I've not encountered any problems with upgrading - Everything still works 100%.

I'm not sure what the changes are - You'll have to review the Changelogs.

here are some of the changes:
http://mum.mikrotik.com/presentations/US07/v3.pdf

here are some of the changes:
http://mum.mikrotik.com/presentations/US07/v3.pdf

That was a very good read!
Thanks for posting

there are a whole bunch of more new features, but this is the newest document i could find online.