It depends on what you've installed as to what appears in cron.daily.
For the most part though it's stuff which is rebuilding generally static databases, updating logfiles, and doing various maintenance routines on your machine.
What you won't see in top is something like :
/etc/cron.daily/somescript [user] [cpu] [mem] [blah]
If you look at the scripts - and the files in /etc/cron.daily are just scripts, you'll see that they launch a program specifically.
So, in the slocate.cron job you might see :
/usr/bin/updatedb -f "nfs,smbfs,ncpfs,proc,devpts" -e "/tmp,/var/tmp,/usr/tmp,/afs,/net"
and that's what you'd see in top. Rather than the script name of \etc\cron.daily\slocate.cron
That's partly because that's the way that scripts work, and partly because that's the way that Linux displays running processes and deals with threads.
Um.. Be happy?