3) Hope of future usefulness. This might be counted as speculation, or at least hedging against BTC. This might be where XCN fits in. I have no idea if the blockchain will be such a problem that it hinders BTC eventually. I don't think it's a real problem right now.
Cryptonite could be useful right now if we had merchants because secure 0-conf transactions are possible when using withdrawal limits correctly, and instant secure transactions are something cryptocurrency desperately needs. The large BTC blockchain will never destroy Bitcoin, but it is already a hindrance to many people, for example I wont run a full Bitcoin node because I don't want to waste the disk space or bandwidth required to download the full chain. But with Cryptonite the network doesn't need to become increasingly centralized only by nodes capable of handling the full blockchain. A few years from now when the Bitcoin blockchain is over 100GB in size, the Cryptonite synchronization time will still be extremely fast and it will be very easy to become a full node and start mining, without wasting a huge amount of disk space of bandwidth. The level of scalability Cryptonite offers is far superior to any other altcoin out there.
The bitcoin blockchain is a rather big concern for the bitcoin foundation. They know it's an issue and they are worried about it...
For this same reason a lot of bitcoin users/hodlers are also concerned.
XCN price fell heavy because of lack of liquidity and then a ~100K sale @ Poloni.
It simply looks like someone sold into walls to drop the price & get that big chunk and a discount price. Simple manipulation imo.
Then again... I'm no expert

Just my 2XCN.