ilya@localhost /opt/chromium.org/chrome-linux $ sudo emerge bluez-utils bluez-libs
Calculating dependencies... done!
[ebuild  N    ] net-wireless/bluez-libs-3.36  USE="-debug" 
[ebuild  N    ] net-wireless/bluez-utils-3.36  USE="alsa cups -debug -examples -gstreamer -old-daemons -test-programs -usb" 
[blocks B     ] net-wireless/bluez ("net-wireless/bluez" is blocking net-wireless/bluez-libs-3.36, net-wireless/bluez-utils-3.36)
[blocks B     ] net-wireless/bluez-utils ("net-wireless/bluez-utils" is blocking net-wireless/bluez-4.39-r2)
[blocks B     ] net-wireless/bluez-libs ("net-wireless/bluez-libs" is blocking net-wireless/bluez-4.39-r2)

 * Error: The above package list contains packages which cannot be
 * installed at the same time on the same system.

  ('ebuild', '/', 'net-wireless/bluez-libs-3.36', 'merge') pulled in by
    bluez-libs
    >=net-wireless/bluez-libs-3.36 required by ('ebuild', '/', 'net-wireless/bluez-utils-3.36', 'merge')

  ('installed', '/', 'net-wireless/bluez-4.39-r2', 'nomerge') pulled in by
    net-wireless/bluez required by world

  ('ebuild', '/', 'net-wireless/bluez-utils-3.36', 'merge') pulled in by
    bluez-utils


For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):

http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked