Pretty much all the bases have been covered from you people. My 2 cents is this:
The rules have changed. PS1 launched their 1st strike in '95, and Nintendo was cocky enough to release N64 a year later (Even delaying it from April to September). Sega also had some console, named after some planet, Saturn was it?
Fast foward to 2000. PS2 launches their 2nd strike, despite one of the weakest launches in Video Game history. but hey, when you're first you can get away with it. Nintendo overestimated its prowess, saying "Hey lets wait till 01."
2001, Software giant Microsoft enters the foray and by some miricle/coincidence brought in the launch title that people still talk about: Halo. What did nintendo have up their sleeve? A purple box and Luigi with a Vacum cleaner (Nintendo played it smart by also releasing Jet Black.) And before I get speared, Nintendo unveiled the new Zelda in the form of a cartoon. Simple rule of Psychology, 1st impressions are important and very hard to erase. I know a good deal of people (myself included) who pretty much went "What in the..." when the 1st screens of Zelda were shown. Granted, as time grew on, Surprise and anger gave way to patience and understanding to those who love Nintendo, not those who probably to this day say Zelda is kiddie and when this game starts getting awards, will be scratching their heads. Also at 01, PS2 had their two home run hitters, namely GTA 3 and FFX. Casual gamers scratched their heads at Pikmin, and Luigi's Vacum was no match Yuna's Summons and Halo's verstility.
Holiday season 2002, by some fluke Splinter Cell was able to topple Metroid Prime, despite being a more verstile game. and GTA Vice city's nickname should be "Sponge" because it sucked up sales in its opening weekend.
What will happen next? Nintendo won't be so cocky this time around, and will play to win. No more year behind launch dates, definately get a good launch game.
The future of Game Boy? Nothing to worry about N-Gage, it may be able to run Tomb raider, but I'd just as soon buy an Xbox and a slew of games (I might anyway, 179 looks feasible.) and have more fun. PlayStationPortable? Be afraid. When a company like Take Two (they made around 77 Million Dollars 2002) says they won't make games for GBA because it won't reach their "audience" and decide to make games for PSP, Nintendo will be in a world of hurt. They're safe now, but they're gonna have to be aggressive; GBA is the last haven of classic gaming.
That's my 2 cents, some of these figures were brought to by CNN/Money's website.