Nintendo's new Mario Kart Wii features a bunch of new tracks for the Mushroom Kingdom crew to explore, but the game also revisits tracks from previous games in the series.  While this isn't the first time a Mario Kart game has looked in its own rear-view mirror (both Mario Kart Super Circuit and Mario Kart DS included sets of retro tracks), for some reason seeing old courses reborn this time feels not quite right.  I couldn't figure out why I felt that way until I saw these videos from VideoGamer.com in which the original tracks from Mario Kart 64 and Mario Kart: Double Dash!! are put up in a side-by-side comparison with their Mario Kart Wii counterparts. That's when I had a flashback to a chemistry class from my college years.  The final exam in that course consisted of both new questions and questions lifted verbatim from previous exams, and most of the time the old questions that returned for an encore were the most frustrating parts of the previous tests.  I didn't care for Mario Kart 64's Sherbet Land when it was new (damn penguins always diving in front of my kart!) and I can't say I'm looking forward to slogging through it again now.  That's the risk developers take when they reintroduce old content in new packages.  People go into old levels with preconceived notions and expectations (including knee-jerk reactions, such as my issue with Sherbet Land), while new material is typically given the benefit of the doubt.