I haven't validated that this would work, but my initial approach would be to add a list to the MySites for posting the status updates to and then for each person's display, pull the statuses for everyone in the colleague list ordered chronologically.
If it is too difficult to get it working with the lists in the individual MySite site collections you could potentially put a central list on a site that cannot be navigated to and use that as the data store.
I talked to somebody else that mentioned trying to aggregate blogs in a similiar manner. You could always add a blog link to the user's profile so that you know where to pull the data from.
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