Agreed with ericsson. The answer is none.

And the Nokia will not open the UI to other vendors.

So, I dont think big vendor, such as motorola, sonyericsson, htc, samsung etc will use MeeGo.

And MeeGo may be appear at many place, such as in tablet, or in your car (actually, there are few products now), but it cannot be the reason for the success of MeeGo. Android can do the same thing.

If there is no 'killer advantages' on MeeGo,

then the apps & developers of iOS & Android will be dominant Pros to beat MeeGo.

Because they already exist and do quite well, why should I change to a new one with the same function ?

When Android came out, iPhone is still accumulating users, now both iOS and Android become stronger and stronger. WP7 is also a big player.

But when N9 release on 2011, it is too late.
The smartphone market has been occupied by iOS, Android and WP7 !