Anime movie "The☆Uchuu Show (tentative title)" was re-announced at Tokyo International Anime Fair 2009. It was announced in Newtype magazine January issue 2008 that the movie will be premiered in 2008, but no further information had not been given since then.

Key illustration shown at TAF 2009

Staff
Original Story: BESAME MUCHO ("Kamichu!", the joint pseudonym of Ochikoshi Tomonori, Masunari Kouji, and Kurata Hideyuki)
Director: Masunari Kouji ("Kamichu!", "R.O.D. TV")
Scenario: Kurata Hideyuki ("Kamichu!", "Kannagi")
Character Designer: Ishihama Masashi ("Welcome to the NHK", "Speed Grapher")
Production Studio: A-1 Pictures Inc.

Synopsis
Koyama Natsuki is an 11 year old girl and moves in the countryside. During the summer vacation she experiences a mysterious adventure with her four classmates.

Source: Japanimate.com
Source: MOONPHASE (Jan 2008)

Updated
According to Animage Original, the official title was announced to be "Uchuu Show e Youkoso". The movie will be premiered in 2010.

Source: Scan of Animage Original

Updated on February 11
Film will have its premiere at the 60th International Film Festival in Berlin on February 18.

Source: Official site of the festival

Thanks to De-JaY for the tip.