I suspect that there are a lot of reasons including:

Certification issues
Availible engineering resources
Slow implementation of LPV approaches by FAA

There are many tens of thousands of 430s and 530 installed and upgrading
them represents a lot of revenue for Garmin, so I doubt that they are just
sitting on their hands.

Mike
MU-2


wrote in message
oups.com...
Why is it taking forever?

Probably because it can.

Bill Hale