According to Rossi's autobiography, before going to Yamaha he also considered going to Ducati. However, when he met Ducati's "officials" he got an impression of corporate point of view very close to that of Honda: The bike is first, the rider second. Since his first and foremost reason for abandoning Honda was exactly this kind of thinking he naturally went with Yamaha which (according to Rossi always) seemed troubled and willing to follow every one of his whims. History proved they were right...
As far as Pedrosa is concerned, he is very fast and he certainly has the "killer instinct" (literally or not
) that his team-mate lacks. I believe he will dominate MotoGP after Rossi's departure (not to the extent that Rossi achieved however) but boy, how dull will it be made, he hardly seems happy even when he wins a race... I'm on with Capirex myself, always exerting positive energy and fights like a tiger given half a chance...