I love everything Nintendo. I guess it comes from the fact that all i ever played as a kid was a nintendo console. So having a nintendo upbringing had a big effect on how i thought as a gamer.
However my fanboyism didn't really come out until the current generation of console gaming, where gaming itself had become pretty stagnant with the continual sequels of WW2 FPS, Driving, and Sporting titles. I started to hate console gaming *cough...EA....cough*.
I was starved of innovation in gaming, and when Nintendo announced the DS and later the Wii (I now randomly say Wiiiiiiiii!!!! at the office in Homer Simpsons' voice), it seemed that gaming was (and is now) getting an injection of freshness.
I think subjecting the term 'Fanboyism' to just a gaming fan is quite narrow-minded by a lot of people. I think we have reached a stage in civilisation where we can call anyone a fanboy/girl based on their favorite sporting team, yet calling anyone a fanboy instantly refers to them being a gamer. Now i would like to see the word 'Fanboy' start to be used outside the realm of gaming. But that's an aside back on topic...
I think of the gaming industry as a bit of a soap opera. There is gossip (in the form of rumors), and twists (as in new announcements such as the delay of PS3 till march...."laugh @ you SONY!!!")... and of course our favorite characters (in the form of the big 3). It fun to watch all the companies duke it out for our hard-earned cash, and it fun to interact as the fans duke it out on the sidelines.
So i say fanboyism is fun, if you don't take it seriously, i mean hey it beats watching paint dry waiting for the real 'next generation' of gaming begins(thats another 5 months worth of watching for you SONY Boys!!...muahahahahaha!!!!)... ahem...excuse me.