I think ASIC miners will have an effect on the Bitcoin economy just not sure if it will be bad or just like the move from CPU's to GPU's. I do think that alt coins such as Litecoin will play a part in the future of crypto-currency.

At the end of the day this is one massive experiment and is still too young to predict what will happen, anyone that says that they know is a liar.

We should be trying to think about what we do know and how that could effect Bitcoin, like the future of the internet. Cisco predicts that around 50 billion devices will be connected to the internet by 2020 (over the around 8.7 billion of 2013). This will help Bitcoin/crypto-currency's get into mainstream because billions of people will be using the internet for purchasing products/services and with such a large number of people using the internet, digital currency would look more attractive to mainstream users/business owners to use over conventional USD because of low transaction fee's, anonymity etc (especially with LTC faster transaction times) .

Bottom line is if the internet is going to get as big as Cisco predicts it is then I see a bright future for crypto-currencies in general.