The basic principle behind the plugin does not require updating. (It's an engine, remaining fairly static). So that's part of it. Other reasons include licensing agreements, nutting out what additional / new functionality we want in and so forth.
So that is why it 'seems' so old. And yes, we are updating it. When we have a new version ready for release it will go public.
Just an update, because I know that a lot of people are looking forward to a new version of PureSight. The dev and QA work on this is progressing at a rapid pace at the moment, the features are all in, etc. and it's looking real good.
I'll let you know when we've got a time-frame for release. Hopefully real soon.