Actually there are still some 64 games coming out. They are all homebrew of course but they are happening. Infact, have you ever heard of Ben Heck? He specializes in making portable video game systems such as: sega genesis, SNES, NES and many more. He even made an xbox 360 laptop. but anyway, some of his friends or somthing are making a game were you play as Ben Heck, its called Grand Theft Portable... and yes, they are making it for nintendo 64. if you are interested go to
The Official Site of Benjamin J Heckendorn and click on discuss games and tech in our forums, then click on grand theft portable and you can find out all you want to know. and if im not mistaken when they finish the game copies will be up for sale. Also, a new sega genesis game just came out recentaly... i believe it was an rpg. oh and i happen to love dreamcast, expecially the mods and homebrew games that come out for it.