Back in the days of old most European TVs could only handle a 50Hz picture so when it came to PAL releases for the Sega Megadrive, Super Nintendo, N64, etc the games would run substantially slower than their NTSC counterparts and have black on-screen borders. Starwing (AKA starfox) was one such lazy port, the letterbox effect was a real let down when playing this after seeing it on a 'grey import' SNES beforehand.
Some games however like Super Mario Kart were optmised for PAL so ran at a comparable speed to their NTSC counterparts. Other games like Mario 64 had tiny borders and was optimised for the PAL region. Most however were not optimised even in the Nintendo 64 era (with the exception of RARE published titles).
Nintendo obviously couldn't just give PAL regions NTSC games now in 2006 as there would be numerous legal issues involved, in addition NTSC games won't have the European languages. The credits and title screens are often different so it's not that straight forward.
The flustrating issue is Nintendo of Europe do not appear to have made any provision to force a 60Hz mode for the games that clearly need it. The end result is Europe gets shafted with an inferior product!
Using the 60Hz option in the PAL Wii's mention does not make any difference to this. Hopefully if they get enough complaints a software based solution could be made available to force 60Hz modes on these classic titles for the PAL regions. Until this time be warned Nintendo weren't joking when they promised the authentic experience!