These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 0.97 s (backtrack: 0/20).

[ebuild  N     ] acct-group/nagios-0-r3::gentoo  0 KiB
[ebuild  N     ] acct-user/nagios-0-r3::gentoo  0 KiB
[ebuild  N     ] net-analyzer/nagios-check_glsa2-20120930-r1::gentoo  2 KiB

Total: 3 packages (3 new), Size of downloads: 2 KiB