Yeah, a bit of a disappointment for sure. The main problem has been the complexity of writing importers, some are fairly easy, some are very troublesome to get right since each one currently has to be written from scratch.
I'm working with a couple people that may be doing an entire import system for version 8. Still in the planning state at this point, but the goal is for a system to allow for quicker turnaround time. Instead of having to write an entire importer each time, we'll just need to write some functions to grab the data we need out of what we're importing from. We also plan on having the ability to only import certain portions instead of having to import the entire forum.