I just had a chat on the #haiku channel on IRC.
I was planning to switch from Ubuntu to some lightweight OS (any other linux flavor).
This is just in its initial stages. Not many programs have been ported to work on this and it's based on the BeOS.
I asked about anything for web dev (since that's what I do), and it seems that the most they support (for webdev at the moment) is the web browser BeZilla (Firefox 2.5) or NetSurf (from BeOS). Java isn't supported yet.
Again, Haiku, as stated isn't a linux flavor, it's based on BeOS.
P.S: I have nothing against Haiku, when most programs are supported, I plan to try this out. A brand new OS with a kernel from ground up, seems like a fresh breath of air. Congrats to the Haiku team.