I've got a bunch of thoughts around this:
- Extender isn't dead, if you like it, its still available from eOne.
- Developers hated Extender but it was really nice to have for mods where using a developer was really overkill.
- Dynamics AX has a reputation for being extremely flexible but difficult to implement quickly and consistently. It's getting better at that. GP has a repuation for quick, consistent implementations but its not as customizable as AX. Extender went a long way toward making customization concerns go away. Especially since the Extender fields would upgrade.. It seemed as if GP and AX were moving toward each other in terms of both consistency and flexibility. I consider the loss of Extender a step backward.
- I've heard from a number of people that the Microsoft Dynamics GP team is shedding products where Microsoft paid outside developers to maintain parts of GP. These include Extender, Audit Trails and the Concur connector. This seems to be a cyclical process that Microsoft periodically goes through. Then at some undetermined point in the future they realize that they have too many developers on payroll and the pendulum swings the other way.