> > 	the approach I like the best is the openbsd one, with a bit of clever
> > 	backward compat code in last(1) and other tools.  any comments?
> 
> Are there good reasons for keeping a binary format?

You're suggesting a textual format here, right? It's not clear what you
mean.

WRT reading the old files - personally, I'd rather see a utility that
converts from the old format to new, rather than adding baggage. Perhaps
that could be part of sysinst.

Andrew