Before I say anything else, I admit up front that I am a a big meanie 
Having said that, I look at the announcements that get put up.
You have some announcements that are specifically inviting discussion:
* Asking what threads are worth saving)
http://enworld.cyberstreet.com/showthread.php?s=&threadid=27672
Then you have other ones that are more narrowly defined as announcements plain and simple:
* The more recent request to lighten up on OT posting
http://enworld.cyberstreet.com/showthread.php?s=&threadid=55651
It is this second type of announcement that I draw your attention to. You'll note in the thread that it starts to veer off into random comments, etc. from people. This (in my mind - and, yes, I remind you I am a meanie so this may not apply to others' respective opinions) lessens the impact of the announcement that is being made.
Might you consider that for those type of announcements (type 2, not type 1) that after they are posted they get locked. Thus, no more posts or discussion about it - just the one post in the thread acting as a very specific and focused announcement as it is meant to be.
If people want to discuss it, they can discuss it in Meta (where discussion on things about the boards should be) and leave the post as its own announcement (not touched or lessened by discussion).
Anyway -- that's just my thoughts. I offer it up as a suggestion if the Mods like the idea. I do understand the basis that I am a meanie and no doubt if used by the mods this suggestion would only be seen by the masses as a mod's attempt to rule with an iron fist * -- so no harm will be done if you decide it isn't the way you want to go
* Since someone may see it as pre-emptively quelling discussion - since it is. Of course, simply putting in a message thath people can go to meta to discuss the topic if they want may take care of that ...

(Obviously, this suggestion is not being made for the type I announcement where discussion is purposely being sought).

Having said that, I look at the announcements that get put up.
You have some announcements that are specifically inviting discussion:
* Asking what threads are worth saving)
http://enworld.cyberstreet.com/showthread.php?s=&threadid=27672
Then you have other ones that are more narrowly defined as announcements plain and simple:
* The more recent request to lighten up on OT posting
http://enworld.cyberstreet.com/showthread.php?s=&threadid=55651
It is this second type of announcement that I draw your attention to. You'll note in the thread that it starts to veer off into random comments, etc. from people. This (in my mind - and, yes, I remind you I am a meanie so this may not apply to others' respective opinions) lessens the impact of the announcement that is being made.
Might you consider that for those type of announcements (type 2, not type 1) that after they are posted they get locked. Thus, no more posts or discussion about it - just the one post in the thread acting as a very specific and focused announcement as it is meant to be.
If people want to discuss it, they can discuss it in Meta (where discussion on things about the boards should be) and leave the post as its own announcement (not touched or lessened by discussion).
Anyway -- that's just my thoughts. I offer it up as a suggestion if the Mods like the idea. I do understand the basis that I am a meanie and no doubt if used by the mods this suggestion would only be seen by the masses as a mod's attempt to rule with an iron fist * -- so no harm will be done if you decide it isn't the way you want to go

* Since someone may see it as pre-emptively quelling discussion - since it is. Of course, simply putting in a message thath people can go to meta to discuss the topic if they want may take care of that ...

(Obviously, this suggestion is not being made for the type I announcement where discussion is purposely being sought).