Heh. Obsolete just means in terms of marketing, it's going to be off the shelves soon, which means the accessories get cheap. (LoZ: Twilight Princess was considered the last flagship title for the Gamecube, focus has moved to the Wii) Doesn't mean the system is bad. Kids can have a great time bashing on each other with an old N-64 and the original Smash Bros, in fact, that's a used system I recommend to people with small kids. That and Mario Kart will keep them happy for hours, plus the carts are less prone to destruction than CDs.
In fact, there's a Retro Gamer magazine out there now, and I myself have a Dreamcast, Saturn, Genesis and NES that are still plugged in and work, even a vintage 1978 Atari 2600.
Good games don't go obsolete if they're fun, the units just go off the market in terms of what's the latest thing.