http://wordpress.org/extend/plugins/about/
http://wordpress.org/extend/plugins/about/guidelines/

In specific, the "powered by" (#10) guideline, which reads:

The plugin must not embed external links on the public site (like a "powered by" link) without explicitly asking the user's permission. Any such options in the plugin must default to NOT show the link.

Once you have corrected the issue, or if you have any questions, please reply and let us know.

Please send a link so the completed plugin can be downloaded. Alternately you can reply to this and send a .zip or .rar file. As this is for a new plugin request, please reply within seven days of this email or we will reject your plugin.

All plugins are expected to be submitted with the code complete and ready to go, including a valid readme.txt file. Either you did not include a direct link to your code with your submission, or the link you provided was invalid/inaccessible. Could you please reply with a link so the plugin can be downloaded? Alternately you can reply to this and attach your .zip or .rar file.

Note: If you submitted a link to a third-party site like RapidShare, DropBox, or Google, and you are receiving this email, please do not just send the same link. We probably had issues getting it to load, so sending the same link will likely get you the same reply. If you need a place to version control your code while you work on it, you can use GitHub to safely host your code while you're developing it.

Please reply with 7 days. If a reply is not received the submission will be rejected and you will have to submit the plugin again, with code, should you want your plugin hosted.

Thanks.