When using Enhanced rich text box in SharePoint 2010 / 2007, it doesn’t give the users the ability to insert EMBED / OBJECT tags into the content. Even if inserted, these tags will be removed once the item is saved. One of the important feature that users want is to embed the OBJECT tag (YouTube Video for example) while they are creating a Blog Post.
Found couple of Good Articles which i liked and are handy. Below are the links.