Ruby 1.9.2 release plan is unveiled

1 week ago, in ruby-core mailing list, Release plan of Ruby 1.9.2 is unveiled.

- 31 Mar. freeze the spec
- 30 Apr. freeze the code
- 31 May. release 1.9.2-preview2
- 30 Jun. release 1.9.2-rc
- 31 Jul. release 1.9.2-p0