Currently (in terms of days and weeks, rather than minutes and hours, as I'm at my day job right now), I'm focussing on researching/writing about Lovecraft's Kingsport for Call of Cthulhu, as well as researching/writing for an ongoing Pendragon campaign and an Orpheus one. I've been adding elements of the greater World of Darkness to my Orpheus campaign, and I'm tempted to write that up as a cross-over book for the Storytellers Vault.
And maybe add an appendix for updating the timeline from the 2000s to the 2020s, as well as some bits and pieces about the cities I've used.
It strikes me that the whole Orpheus campaign could work really well as a Gehenna/Apocalypse/Ascension end of campaign scenario for any of the main WoD game lines, so it could be that writing up such a book would allow crossovers in both directions.