To many cartridges....
The only thing I would like to see is a true 22LR magnum. Just stretch it out just a bit more, another 8-10% powder, make it fully backwards compatible with 22LR case and rim dimensions.
I've got a short brief written that I'm tempted to post up and send out to ammo companies...
But I've only been doing this hobby for 3 years and what the [bleep] do I really know...