I would guess they want to keep it - there are a lot of company advanced engineering projects run on Arduino and when those prove useful (most don't) the company starts looking for how to make it production. Thus having Arduino as a push to their chips is a useful in to more companies.

Of course companies change directions all the time. I wouldn't surprise me if the people who bought Arduino believe the above vision, but there are other political factions that will try to kill it.