'the medium is the message' and 'messages by the medium' - corporate social media.

Everyone remembers 'The Medium is the Message' - it's succinct, and is a great reminder that means of delivery alters potential interpretation.  It's a classic for a reason.

We're reaching the era of 'Message for the Medium' - your content will have to be defined by, and tailored to, the limitations and most importantly cultures of each medium.  Regurgitating the same creative across social networks, banner ads, billboards and TV spots won't work unless your creative operates like a native, to the natives on each platform.  Awkwardness is tantamount to invasion, and will be responded to as such.

Corporate blogging is almost always terrible, mostly because it's usually press release content, advertising content, or marketing content designed for another channel, spooged into blog form.

[Spooged is, if I remember right, taken from Douglas Coupland's Microserfs - the context is in taking an application made for one OS, and then screwing with it until it works on another one.]

Spooging content is poised to become an even bigger problem, for many reasons.  First, social media has larger corporations in a panic, and they are starting to demand a presence without understanding that they don't fit.  Second, old business models are being made less relevant by the second, so content and business plan are being spooged into new media in an attempt to 'modernize' without having to completely re-create a revenue stream.  Third, mobile internet, and mobile social media, are going to be dead easy to sell (who wouldn't want to advertise in someone's pocket) and hard to execute.  The first iteration of this will be horrid, like most first iterations.

Some corporations have such a perfect angle, though, I wish I could convince them to blog just so I could enjoy it.  The one I want most: 3M's Research and Development Division.  A bunch of geniuses with a colossal budget creating tiny outbursts of the future, and sharing it with us step by step and constructive narratives by both the research team, and the project.  But it won't happen, due to trade secrets and the simple fact that it's too alien a concept for the higher ups to approve.  But it's an example where a corporate element would actually fit into the character and requirements of blogging, as opposed to trying to turn the medium into something more familiar.