Here is a very quick and arbitrarily abstract Venn diagram of the cryptocurrency ecosystem with an emphasis on the Bitcoin ecosystem and the fundamentally different fields of discussion and development that are currently operational and will be operational in the near future:



There already is an "Alternate Cryptocurrencies" sub-forum. There are very clear use cases for a dedicated "Bitcoin 2.0 Technology" sub-forum which can be further subdivided into "Sidechains" and "Metacoins".