This accelerator seems very powerful, A500 owners really are getting spoiled for choice
Straaange that news post didn't have any photos 2 months before release. Which makes me think it will be delayed. But that's maybe only negative speculation.
To address some stuff said above, acceleration on A500 is useful for anyone who uses Workbench, just like on all other Amigas. The faster the CPU, the better the experience. Some may also
have a few special uses that makes them want a 68040 or 68060.
The reason why nobody builds a 68040 or 68060 accelerator anymore is that they would have to source used CPUs and give warranty on the accelerator with them inserted. 68030 CPUs, at least certain models, can be ordered NOS in quantity from Hong Kong cheaply.
I wouldn't mind seeing an upgrade path for people who do have old 68040/68060 accelerators and want to swap out the board and keep the CPU. But that's a little bit less of a "consumer product", even if most of the accelerators require quite a bit from the consumer already, so I really think they could normal, successful products, even when delivered without a CPU.
These CPUs are quite a step up from 030 and below, in performance but basically in every aspect imaginable, really quality products. So I hope it happens.