Yahoo's, yes. Apparently you didn't look at Yahoo's web site, because
there's a very evident "Export" link visible on the COntacts page and an
"Export to Outlook" button on the Export page.
For Hotmail, you should connect to the account using the Hotmail Connector
and then your Hotmail contacts should be available in Outlook. You can
either transfer them to your main Contacts folder or simply use your Hotmail
account via the Connector.