Gamespot has done a neat little
preview for the GBM. It is slated to come out on Sept 19 (but it doesnt say if thats the date for Japan or U.S). It will go on sale for $99.
hum... it looks really impressive, though the screen is a little smaller but brighter then the SP's. Another thing it wont be backwards compatible with GBC.
I hope this brings the price for SP down so i can finally get one
(Images taken from Gamespot.)