There was a collective sob fest on TH's journal when she confirmed her editor wasn't interested in another Smoke book, she did mention that she plans to revisit Tony's character through short stories.

I am holding out a bit of hope that the renewed popularity in the Blood Books may translate into more sales for Smoke and she will be 'allowed' to write Book 4. Or that she follows the Kelley Armstrong route and posts the (supposedly) unmarketable storylines as novellas free on a website.