As Line6Tony says, Gearbox has been placed as a Legacy product for quite a while now with no plans to develop it any further.
However, I hope that Line 6 will make the investment into Gearbox after hearing that there are so many people still using the X3. We all have our reasons for not going to the HD platform. My reason for not going to the HD platform is because of the lack of bass amp/cab modeling. It seems that Line 6 has abandoned the bass players. I'm sure it was a business/financial decision. As time went on the Bass Variax and Bass POD models were discontinued.
My hope, and I may be naive to think this, is that Line 6 will start to restart their Bass effects and Amp/Cab models in their HD line, but until this happens Gearbox should be updated to support the bass players and those who are still using the X3 and Xt models.
Do those who make the decisions read these forums? Is there another place to voice our options and suggestions?