you will have full support for this module for as long as you need it.  I monitor the forums daily and respond to all posts. Version 4 is not dead, it's just taken a right-turn. The original plan for ver4 came out in the DNN 4.X days and development started, in fact a fully functional ver 4 runtime is in use at http://www.gooddogs.com/dotnetnuke on the downloads page.  Then the corp came out with their DNN 5.X roadmap and there was some significant overlap in functionality.  I put the module on hold because I didn't want to spend time writing code that would be a functional duplicate of core functionality.  DNN 5.X has been slow in coming and the repository module has been on hold for quite some time as I waited to see where the corp was going.

There actually have been posts occassionally on the status of ver 4, whenever I've been asked, I've responded.

However, I am now ramping up again and version 4 is coming out of retirement :)  I'll have more information in the next few weeks, an updated architectural diagram, road map and development plan.  My 'goal' is that the 'worst case scenario' is that a Repository version 4 beta will be available at OpenForce'09 in Vegas this November.