The next major consideration in keeping your community informed involves determining the appropriate level of detail you're going to provide. Consider a website that wants to inform its audience about new features that will be coming to the site over the next several months. The webmaster would likely offer vague descriptions of the new features and equally vague timelines for their deployment. The level of detail of this information would be perfectly acceptable for most website communities.
Contrast the previous scenario with a website that wants to inform its community of some scheduled downtime. In this case, the community will seek a greater level of detail both for the reasons behind the downtime as well as the specific times when the service they use will go down and then return.
Finally the third major consideration is that of timeliness. Most all information that you will want to share will be time sensitive in some manner. Sales come and go, new releases are only new for a certain time and future plans become past development as time moves forward.
So you need to consider the need for immediate distribution of the information as well as the length of time that information will be valid. The timelines involved in keeping your community informed will have an influence on each of the issues we've previously discussed.