Hello. Since this isn't the first time the vlan package with its deprecated vconfig command causes discussions I've gone ahead and uploaded a new version of the package to experimental. See vlan 2.0 also available from https://people.debian.org/~ah/vlan-2.0/ for the impatient who doesn't want to wait for archive updates and mirror syncs.
It would be very welcome if brave souls would be so kind to test if this version of the package works (within the same limitations as the old) and report back. For background info see http://bugs.debian.org/501402 Regards, Andreas Henriksson