In a recent commit message to the 1.3 branch:

> Add forward-compatibility with new NetBSD MBR partition-id 169
> (0xa9).  Warn about old-style 165 partitions with a reference to
> installboot(8) for details on when and how to upgrade bootblocks and
> partition IDs.  Do fresh installs using the new ID.  Done via patch
> because it's a long list of changes which didn't quite apply
> cleanly.  (jonathan)

This in a patch release?  Forward compatibility is fine, but when I or
the users I support upgrade from 1.3.2 to 1.3.3, they really should
not be told to diddle with their partition tables at that time.
Likewise, an install of a 1.3.3 system probably should not be
partition-ID-incompatible with a 1.3.2 kernel.