You can get one if your altcoin's hash rate exceeds 100 gh/s... or equivalent for scrypt sound fair?
Why so complicated? It'd be hard to agree on equivalents to every new algorithm, and gh/s for proof of stake coins just represents the value of new coins, and with merged mining ...
It'd be much simpler to go by market capitalisation. Every crypto over 1Mio USD should get it's subforum.