Ok, got this working!
So far it seems a lot better than SIP, as I can use some sort of BLF on side keys of the phone, direct dial, directory, etc.
v4*CLI> sccp show version
Skinny Client Control Protocol (SCCP). Release: TRUNK - 1365 (built by 'root' on '2010-03-13 17:07:17 UTC')
v4*CLI> sccp show devices
v4*CLI>
NAME ADDRESS MAC Reg. State
======================================== ==================== ================ ==========
7156 172.16.0.161 SEP00179592DA9E OK
v4*CLI>
The only caveat so far, working with sail, is that anytime I need to edit/add/remove any extension, the system will wipe off all of my files in the tftpboot. Even thou I still have another cisco phone working with SIP.