Good news for those of you who lack patience: Both of the above-mentioned reasons are covered by and in the following video:
Yep, tomorrow will be the best day of 2011 because that's when Minna no Rhythm Tengoku (aka Rhythm Heaven Wii) will hit the streets in Japan.
Real talk: Based on what I've seen of it thus far, I fully expect Rhythm Heaven Wii--which has yet to receive a European or North American release date (harrumph!)--to compete with the GBA original for the title of "Best Rhythm Tengoku Game."
Admittedly, it'll only be competing against two other games--the first of which was released for the GBA in 2006 and the second of which was released for the DS in 2008/2009--but both of those titles are among the best rhythm games ever released, so the winner of said contest shouldn't be considered chopped liver.