I actually had a bet on the subject !
apparently there is a big diversity but most aerial tramways (for 30 people or so ) go in less then 8 m/s, and new model go up to even 12 m/s, it all depend on the manufacturer.
you can view some statistics in this site
http://www.seilbahntechnik.net/english.php
just pick the "heavy carriers" and look at their statistics
