Local use flags so far:

dev-db/mariadb:libevent - Use libevent for connection handling
net-dns/unbound:libevent - Use dev-libs/libevent instead of internal
select based events
net-im/bitlbee:libevent - Use libevent for event handling
x11-misc/bmpanel:libevent - Use the libevent event loop interface
net-im/prosody:libevent - Use libevent for event handling

Any objections?

Cheers,

Dirkjan