Even if your marketing team says you don't need a company blog (though you probably do), consider setting up a Web site status blog for your visitors or customers. A status blog is a basic, no-frills site that contains updates and posts concerning a Web site's uptime (and downtime). It's a great way to let people who drop by your site during scheduled maintenance know that you're only down for a while, not down for the count.
The super-popular community Weblog Metafilter recently used its status blog to keep site members in the loop during server maintenance that ended up not quite going as planned. Although the downtime was expected to last, at most, a few hours, it ended up taking days. Members got plenty of updates along the way, and many of the wandering souls ended up entertaining themselves over at Twitter for the duration.
A status blog doesn't have to be elaborate, and doesn't need a special cadre of writers. It's perfectly all right to have the IT department or Web guys update the blog -- in fact it's encouraged.
There's no reason to avoid technical jargon since many of the people reading it will be heavy on the tech knowledge themselves. That said, it's not a bad idea to include at least a sentence or two describing what's going on in laymen's terms for readers without a lot of technical knowledge.
Oh, and don't forget to host your status blog on a separate server so people can still access it when your main site is offline. Otherwise, visitors might be left wondering, "Is it down for everyone or just me?"