I've seen youtube vids of them [coin ship] but I didn't see any that explained that well about them. Looking back at gameplay of SMB3, Mario's sprite looks a lot pudgier than I remember, heh.
Ever since the NSMB on DS, I thought it was a little too easy for Mario to get coins and with the footage of NSMB2 on the 3DS, it seems to be even more easier to get extra lives.