You'll note that uStream has been removed, but only because uStream's functionality, and much more, has now been built into uLink (since 1.5) - so there's no longer any need for a separate component.
We've been working on a major rewrite of uCollab but lately, we've prioritized general improvements of the UnityPark Suite. We're extremely eager to proceed with our plans for uCollab as we know how useful it is. Until then (currently no ETA) we've removed it from the site. Developers whom already downloaded it can still use it of course.
Go, check out the brand new home for our sweet Suite developers (that's you!):