Beyond R1
Initial planning for R2 has started through the "Glass Elevator" project (a reference to the children's novel Charlie and the Great Glass Elevator). The only detail confirmed so far is that it will switch to a current GCC release (namely v4.3.3).
A compatibility layer is planned that will allow applications developed for Haiku R1 to run on Haiku R2 and later. This was mentioned in a discussion on the Haiku mailing list by one of the lead developers, Axel Dörfler. Suggested new features include file indexing on par with Unix's Beagle, Google Desktop and Mac OS X's Spotlight, greater integration of scalable vector graphics into the desktop, proper support for multiple users, and additional kits.
Read more about this topic: Haiku (operating System)