Your wireless can access your LAN clients without any issue so long as you permit it via the rules. My wireless clients connect to my media server which are both on different segments/vlans.
True, any service that utilizes broadcast packets might not work, since that requires you to be on the same network/subnet/switch. Something like DLNA or Homegroups (windows vista/7/8). However there's even a work around for that too, but it's a bit over my head. I was just reading about it via another thread where a guy wanted to access windows shares between two different segments.
WPA2 isn't bullet proof though, and if you have a bored neighbor they can still weasel their way in. Though you're right, it would take considerable amount of time - especially if you're using a solid random password. Though I'm just naturally paranoid, even when it's not needed :-P