It would be great for winchester to make a 22 super mag rimfire from their 17 /nail gun case and chamber it in an ar platform so that we could have it in the uk and also a cheeper but effective training /home defence round.
Ruger to make a 7.62 x39 scout rifle that takes ak mags, is threaded and has a 308 bore so that handloaders can use all 30 calibre bullets.
An accurate , threaded, bolt action 9mm that takes glock mags for quiet, inexpensive(compared to 308 /creedmore), long range /short range practice and small game rifle. Would be great fun for teaching children as well.
A high capacity 28gauge on an ar platform would be a lot of fun, especially with slugs.
Admittedly an odd collection but we're all different.