Well kit, I must say I don't like the DS that much either. The idea of a touchscreen for gameplay doesn't sound good, specially when you have such a small screen. The PSP seems to be the way to go right now on portable systems (widescreen, multimedia support, memory stick slot, remote control, better graphics + better games, etc), and I dare to day it might kill the DS.
BTW, recharable batteries are the only thing you find these days. The technology has improved, so the whole thing about reducing battery life is not nearly as aparent as it did 2 or 3 years ago. I must say that I haven't lost much total battery time recharing my InfoLithium batteries lately.
About the plane thing: Many people say that wifi does not interfere with airplane communtications, and the DS will do the same that a regular winXP machine with wifi does: send out probes until it finds another peer or access point.

Well, thats my opinion, now start the flame war!!!