First of all, some powered hubs does provide power to uplink. Yea, I know they shouldn't, but...

Second, it's not healthy for battery (life) to keep it at max voltage. LiPo's (LiIon's, in particular) like best to be keep between 20-80%. For people working for hours with keyboard/mouse connected to N900, keeping it auto-charged is extremely unhealthy for battery.

Not mentioning plentora of other situations, like calibrating battery chip, etc.

As for "charging only to 100%", what else do You want? Battery exploding due to overcharge?

In any case, invoking charge.sh when someone want charging, is easy enough. You won't get other charging method during hostmode, anyway.

/Estel