Bit more info for you, I've managed to get the latest build of the Linux wallet to compile after some effort (issues with my system rather than with the code) and have been looking at the peer info - there are definitely two forks in existence currently, one is around block 12750 and the other is at block 15000. Looks like the major part of the PoW hash went on one fork but somehow the other one continued and got well behind in blocks whilst the difficulty was adjusting down to the reduced hashpower.
I've been digging a bit more though and its a bit peculiar, with my new daemon it will only sync on the 12750 chain and rejects PoS blocks from the other chain. If I set the conf file so it only connects to nodes on the 15000 blockchain and try resyncing it gets to block 10041 and then just rejects PoS blocks.
As I mentioned before, I'm a tinkerer not a coder, and I don't know the PoS stuff that well but from what I've seen so far I have a suspicion that the dev accidentally released two different versions of the daemon, if you look at this commit from around when the coin was launched there are a couple of key PoS changes made:
https://github.com/RentaMouse/Spark/commit/71d360fdbb18aacf9c49179e0be882f0b9fac289 - the PoW endpoint in the PoS code is changed from 10000 to 14000, and the PoS key is changed. Pre-change daemons could have mined a PoS block after 10000, post change versions wouldnt accept it.
On GitHub there are actually two release versions, 1.0.0 and 1.1.0, looking at the peer info from my daemon there are a few nodes on 1.1.0 but none of those are on the 15k blockchain, which backs up my theory. I suspect Bittrex are running 1.1.0 because they would have compiled from Github and they added the coin later than most....
At the moment its too late for me to decide whether its actually a really bad thing, although I suspect it explains the disappearance of the dev, he may just be running from his backers cos he realised his error a week ago

Quite possibly its not the end of the world as I suspect all the pools will be on the old code, so no miners should lose out on a load of coin, and Bittrex stopped their trading pretty quickly.
What I'm pretty sure of is that I can release an updated version of the wallet which will work properly with the 15000 chain so everyone can get in sync with that.
Discuss away, I'll be back in a few hours....
Releasing an updated version would be perfect, if Dev does not appear we should seriously consider finding a dev that is willing to take over this project.