My friend have read a book about kanji-abolitionists in Japan. So basically, they generally agreed that Kanji was a anachronism and should be abolished. But as for its substitute, they were torn between kana and romaji. The kana-faction and romaji-faction spent much time fighting each other, and kanji was largely left alone.
(yeah, it's from the book, to my friend, to me, and then to you).
Basically, you need a colonial power to push for this. Otherwise social inertia of habit was too strong for a change of script to happen.
As for impacts, it would make the script easier to learn. Although japan was quite literate even before Meiji (More literate than Poland, a latin-alphabet user.) This was probably the reason why the leadership did not feel motivated enough to change the script.
The languages of Korea and China (and probably Vietnam) would be less influenced by Japan, and vice versa. As the three countries now use different systems, they could not just borrow words from each other's language.
I'm not very insistent on culture, but you have to consider the damages. An abrupt change of any script would do irreparable damage to the traditional arts and culture of a nation, including that of the Japanese. It would make the new generation less interested in their old arts, as they now need to cross a language barrier to access their own traditional culture, restricting the talent pool needed to pass on their tradition.