... to lock the user to a particular derivative. This is fine as long as the maufacturer has some users to lock.

If not, that manufacturers might try to second source an already established derivative to try to pull over some of the users from the "first source". Now they need to have some incentive to do so, mainly lower price. And this is hard to achieve, as those who push the ARMs these days do so through giving up their usual margin, in the hope of winning a portion of a rapidly closing market...

However, it's not that unlikely that this will indeed happen after things settle down a bit, maybe in 3-5 years. As an example, see Nuvoton's (ex-Winbond's) '51 offering: they have LPC9xx-pin-compatible models available, while the LPC9xx is not a particularly widespread "standard" line...

JW