Um... Where to begin.

K, so you want a nice easy way of passing a replay to other people without having to use file sharing sites etc. That I get.
You also want a method of doing it via the client.

ATM your current idea just wont work - well the bit where it forces everyone in the server to see it. That's just asking for people to abuse it. Middle of a match & someone decides to play a replay? It'll become the new rage quit -> rejoin.

ATM we have a replay storage thingy on the site. *points at the replay option on the menu bar*
Thing is it's on the forum & not ingame.

An easier & probably better solution would be to add support for that ingame. Add the option to upload a replay to that from ingame & add a browser (with search filters) so people can "play" them from that.

Make more sense?