Instead of answering the question directly, let's do a quick survey of some larger corporations in the space.
This incomplete list illustrates how each company takes a different approach to information, outreach and community building.
The GE Global Research blog is a peek into their industrial research labs and is targeted to the technology set. They have dozens of contributors so the content remains fresh and wide ranging, and they incorporate lots of video.
The Graco blog also has multiple contributors (always a good idea) and focuses primarily on parenting issues.
General Motors' Fastlane blog is "a forum for GM executives to talk about GM's current and future products and services." GM has been in the space for some time, and their blog gets a lot of comments, particularly in the past day or two as the Big Three are all testifying on Capitol Hill in search of a bridge loan to keep them afloat.
Most social media consultants, and I include myself, will say that a corporate blogging no-no is to prattle on about your latest product or service. Instead, you should be attempting to build trust with your community and be a problem solver. These three companies attack this issue in different ways.
GE is speaking to a devoted and passionate audience of science and technology people. GE Research Labs does not really make consumer products so unless you're planning on buying a multi-million dollar medical imaging machine or a pulsed detonation engine (I don't know, either), I think they're right to break this cardinal rule. Their blog is for those who wish to stay on top of new developments.
Graco has a wide range of baby products they sell such as playpens, car seats and strollers. The blog, however, shares experiences and offers advice to the common problems that affect all parents. They do have a channel about their products, but the number of entries there is far outnumbered by those in the "Parenting" or "Babies" channels.
GM's blog, on the other hand, is essentially a series of press releases or talking points posted by execs of the company. To their credit, though, most of the posts receive a LOT of comments and GM seems to let the community say whatever might be on their minds, and things sometimes get a little chippy. I don't think people are feeling too warm and fuzzy towards any of the Big 3 right now, and if you don't believe me, check the comments section.
There are tons of other big companies out there blogging (Coke, Molson, Intel, P&G and Wells Fargo, to name a few. There a good list here if you're interested in seeing what the other guy is doing). The purpose of this post is not to hit you with a laundry list of who's doing what. The point is to get you, your company or your clients seriously thinking about getting involved in the space, spy on your competition, learn from their mistakes and maybe even find something out about these companies you may not have known.
One of these days, "new media" will stop being new. That day is growing ever closer.