Forum Moderators: open
I think you get extra PR boost from being "new." Just because you have an extra Yahoo link.
For the cons:
1) If you have a listing in two yahoo cateogories it might be hard to reconvince them to multiple list.
2) If you are listed in a lot of local/regional yahoos, it will takes awhile for new lsitings to filter down.
You just dont want to be messing around with Yahoo listings.
Shak