Previously, bloggers are strongly advised against deleting blogs and what happens to the blog URL blog URL if you delete the blog. For reasons, see Why you should not delete a blog and what to do if you change the URL of a blog.
However, because Blogger has been informed of spammers grabbing deleted blog URL for spamming purposes, the practice of releasing a blog URL the moment the blog is deleted has been discontinued. Now if any Google Blogger blogger delete his or her blog, the blog URL is no longer released for others to register, but is kept for the original creator to claim back later.
The reason for this post is because of many questions and requests for help related to the above, and rather that repeating the same thing, if I ever get another question related to this, all I need to do is to point them to this post.
The most recent one is about a very fortunate blogger who wanted a particular blogspot URL which had already been registered by someone else who didn't do anything or didn't do much with the blog and the blog had been left neglected. In this particular very rare case, the blogger was able to contact that blog owner who is very cooperative. The blog owner deleted the blog so the intended new owner can claim it. As expected, she could not do so.
However, not all is lost provided the previous owner is willing to cooperate. All she has to do to to contact the previous owner again, requesting him or her to register that deleted blog again, and then invite the intended new owner to become co-author via Dashboard > Settings > Permissions. Once she has accepted the invitation, the cooperative old owner can make her administrator, and then remove himself or herself. Once this is all done, the blog have found a new, loving owner.