Agreed but they have so much cash they could buy a company that does tablets well then rebrand/integrate. Never underestimate what a billion dollars can do given the willpower to use it.
It won't do them any good if they don't have people in house who "get it". Look what happened with the Kin after they acquired Danger.
Edit: another thing, the top dogs in this space (Google and the staggeringly efficient Apple) have a lot of cash and are much more focused. So if they were to go all in in any market segment their money is likely to go a lot further than it would at Microsoft.
