tcpdump-3.4-31 (current) includes arpwatch-2.1a4. Please note that arpwatch is up to arpwatch-2.1a10, to be found at what I believe to be the home site - ftp://ftp.ee.lbl.gov The newer version appears to address some of the issues currently addressed using extra patches and also adds simple new functionality, such as the -n switch which solves the problem of logging a lot of bogons when using aliased IP interfaces.
Upgraded tcpdump*.src.rpm + patches are available (at least for some time) at http://www.netcore.fi/pekkas/linux/ ; too many to attach here neatly. Before prime time, arpwatch would have to be assigned an UID, init.d/arpwatch tweaked and /var/arpwatch owner.group perms changed. This is post a10 issue though.
The new tcpdump on rawhide is still using arpwatch-2.1a4. Sorry, what did I miss?
Wait for tcpdump-3.4-36...