no daemons listening and errata updates (secure or not?)

Hi colleague

I am using Fedora Core as workstation. To lock down the OS, I disable
all network daemons: only dhclient is listening for network
connections. Furthermore I regularly update my installation using yum.
All other setting are out-of-the-box from Red Hat.

Is my simple setup secure to be connected directly to the Internet?
Does an attacker have a chance to break my workstation? How high is
the risk? What can I do to improve the security? How would you break
in my system? Please show me vulnerabilites in my setup.

Nico

---------------------------------------------------------------------------
This list is sponsored by: Norwich University

EARN A MASTER OF SCIENCE IN INFORMATION ASSURANCE - ONLINE
The NSA has designated Norwich University a center of Academic Excellence 
in Information Security. Our program offers unparalleled Infosec management 
education and the case study affords you unmatched consulting experience. 
Using interactive e-Learning technology, you can earn this esteemed degree, 
without disrupting your career or home life.

http://www.msia.norwich.edu/secfocus
---------------------------------------------------------------------------