K-on! First Season Blu-rays Box will be offered with english subtitles.

K-on! First Season Blu-rays Box will be released March 5 in Japan.

It include a lot of special bonus.
- Special Booklet
- 9 postcards
etc...
And there is English subtitles.

ref
http://www.tbs.co.jp/anime/k-on/index-j.html