Marking micro-blogging status messages?

Hi,

I don't think the topic has been raised before on the mailing-list.
Apologies if that has already been addressed.

What is the best way to mark a micro-blogging messages à la Twitter,
identi.ca or any other SMS-like status message?

Looking at schema.org, 'Article' (or a sub-type of 'Article') seems
the closest thing to represent such a message but, depending on how
you see it, you might say that a status message is:
1. an Article with an articleBody and no name
2. an Article with a name and no articleBody

In both cases, the type is too generic to carry the nature of the
message. Would it make sense to add a sub-type 'Status' to 'Article'
and clarify how such messages are to be represented? Or is there
another vocabulary that should be used?

Thanks,
Francois.