Check out what an Eidos representative is saying here:
As you’ll be aware, we’re currently working on a multiplayer game firmly set within the Legacy of Kain universe called Nosgoth, which we’re very proud of. It’s grown in size and scope since its initial conception and we’ll be talking more about it in the future. While we’re not working on a single-player Legacy of Kain game right now, that doesn’t mean it’s not something we’d look at making in the future.
While that doesn’t confirm anything, the fact that they’d be willing to consider it in the future gives me hope.
If Nosgoth does well, SqEn will see that there’s money to be made from the franchise after all. The “previous game(s) sales don’t justify making another one” argument (which I understand was a significant factor in cancelling Dark Prophecy and Dead Sun) will become moot.
I think now, more than ever, the fans are the ones who’ll have to make a difference. The more people buy Nosgoth, or even the other games (now would be a perfect time to round up your collection of you missed any), the higher the chances that the Powers That Be will consider a HD remake of the series or even a new game.
So vote with your wallets, people. Right now, it’s probably the one thing that SqEn & co. will listen to. :)