First, it's hard to compare because they're two different companies. MW has maybe 10 actual employees the rest are concept teams that Sakaguchi puts together of his old friends. They then outsource their games to other companies.

SE on the other hand has numerous different full development teams working on various projects, and they have not one, but 2 flagship RPGs, one of which is the most popular in Japan, the other the most popular in the world.

Second, I think XBox's traditional unpopularity in Japan is something that is changing as we speak. A good number of systems were sold in Japan off of BD alone and I can only imagine what will happen when LO comes out. Take into account Mass Effect and the fact that along with the DS it has possibly the most RPGs being made for it, I think the times are changing, if only a little right now.

Also, I want to refute what Zora said - that Americans "dislike" RPGs. Just because something isn't bought doesn't mean that there is a negative opinion about it, much less an opinion at all. In America the PC contributed to games as the console did in Japan, and because of the mouse and keyboard instead of a controller, we received and played some groundbreaking and amazing titles that are foreign (in 2 senses of the word) in Japan - The RTS with Command & Conquer, the FPS with Doom and then reborn with Half Life, and the PC RPG with Balder's Gate, Ultima, and Everquest. In Japan they are just starting to realize what these games are about just like Americans realized what RPGs are all about with FFVII.

I think we're also going to see Dragon Quest get more popular in the states too. I was under the impression that the Akira Toriyama aspect created more fans, if anything, considering how immensely popular DBZ was. VII was the first game in a while to be brought to the states and VIII received a big push. Although the DS is more a Japanese handheld I think IX will probably follow this trend.

It'll be interesting to see what happens but IMO Sakaguchi was a better producer/coordinator than designer and all of his proteges are now some of the best in the business. Unless he really revolutionizes RPGs once again, I don't see any company, Mistwalker included, topping Final Fantasy and Dragon Quest.