The updated Ubuntu 11.04 "Natty Narwhal" release schedule is available on the Ubuntu Wiki. I say updated because the release schedule was already available for some time, but it had to be reworked because Ubuntu 10.10 Maverick Meerkat will be released on October 10 and not at the end of the month like it was originally planned. Ubuntu 11.04 "Natty Narwhal" will be having 5 alpha releases (10.10 on