Priyank Garg of the Yahoo! Search Team has commented on a easy way of submitting your site to Yahoo! site explorer.
Priyank comments "Now, all you have to do is make sure that 'sitemap.xml' is enabled and your site will be submitted to Yahoo! Site Explorer automatically.
With this feature, new stores as well as existing stores with 'sitemap.xml' enabled will have access to the toolkit inside Site Explorer.
Within a few hours of enabling, you'll be able to locate your indexed pages and the links to your sites, as well as delete pages in the index or rewrite dynamic URLs. To double check if your site was auto-authenticated, take a look in the 'Source' column in the 'My Sites' page in Site Explorer."
This will allow Yahoo! to grow the pages in its search index quite substantially picking up pages that previously it was unable to spider. Well done Yahoo! better late than never.