Blackcoin is the future, here is my thoughts:

To reiterate the obvious points: the network can operate without the need for mining equipment, there is the obvious energy savings

However in addition we need to give people incentives to leave their wallets open as this helps power the network.
More wallets online == more connections == faster everything

Having a PoS coin with minimum days needed to stake be more than a day means people can leave their wallets off for a while before powering back on to try and mint  

8 hours is the perfect time. Not to long, not to short.

Minting is low power and since most people's computing is heading to tablets and smartphones that means Blackcoin is perfect for mobile devices. Blackcoin getting android / iOS wallets would be a huge boon.