I think the standard excuse is that Tom doesn't have a wheel mouse and Dan claims to still use text only. Maybe you could help the cause if you want to donate one. ;-) Of course, I'm sure they are swamped with the latest update, so "no new features" is the party line.
I don't think so, but it would be a nice feature, given that it's very common now for games to use the mouse wheel for weapon selection and the like.