According to the WSJ:

http://www.engadget.com/2012/05/15/google-planning-multiple-nexus-devices-android-jelly-bean/
5 Different Nexus devices to choose from, plus nexus tabletsLikely to be formally revealed at Google I/O, the mega-corp is planning to partner with a variety of OEMs (rather than just one at a time) in order to have up to five Pure Google (read: Nexus) devices available at once. Better still, the whole stable will ship with Android 5.0 (Jelly Bean) and will be sold directly from Google in unlocked form to consumers in America, Europe and Asia.

http://www.engadget.com/2012/05/15/google-planning-multiple-nexus-devices-android-jelly-bean/
