Firstly WP.me claims to be the only two-letter .me domain in the world! From now on every blog and post on WordPress.com will have a WP.me URL, which will be linked in the <head> section of the webpage html using rel=shortlink. WordPress promises these permalinks will stay around the internet forever and they will regularly monitor these urls for spam.
So can you get a short wp.me url for your blog? Sorry, WP.me urls will only work for WordPress.com hosted blogs.