Update: Tuesday, 20 April 2015
New ShadowCore Client Now Available For Public Testing
Our development team has been hard at work integrating new features into ShadowCore that will better support our upcoming ShadowMarket. In order to best support a P2P marketplace environment the ShadowCore client has been updated to prepare the network to switch from using Proof of Stake to Proof of Stake v2. PoS v2’s revised coin weight calculation encourages greater network stability by not factoring in “coin age”. Therefore saving up coin age is no longer possible so nodes will need to be online more in order to get their stake reward. It'll involve a move from scrypt to SHA256 which will mean staking requires less processing power (especially helpful for mobile users wishing to stake their coins). The new system is also designed to solve security issues which made PoS v1 coins open to certain theoretical attacks. For more information see Blackcoin's Proof-of-Stake Protocol v2 white paper.
Great news, thanks!
So how will some wallets using SHA-256 while some others are using Scrypt on the same blockchain affect things? It seems to me like the two algorithms would be at war with one another, with one not accepting the solved blocks of the other.
Once testing is finished and the hard fork is complete everyone will be using sha256 for PoS until then it remains as-is...