After upgrading the portage to 2.1.7, I started to get things like below when running emerge:

!!! The following installed packages are masked:
- dev-java/sun-jdk-1.6.0.17 (masked by: dlj-1.1 license(s))
A copy of the 'dlj-1.1' license is located at '/usr/portage/licenses/dlj-1.1'.
 
- net-im/skype-2.0.0.72 (masked by: skype-eula license(s))
A copy of the 'skype-eula' license is located at '/usr/portage/licenses/skype-eula'.
 
- dev-java/sun-jre-bin-1.6.0.17 (masked by: dlj-1.1 license(s))
For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.

So, there is something about license. There is a bug opened for this. See here. To accept all licenses by default, just edit /etc/make.conf, and add

# Accept any license
ACCEPT_LICENSE="*"

That should take care of it.