I recently had a query about which order the Shader and Nameless books should be read in. Below is the ideal, although Nameless can also be read alone:
Best Laid Plans
The Unweaving (due out this spring)
The Archon's Assassin (due out late summer)
Rise of the Nameless Dwarf (2013)
A Dark Perdurance (2013)
The Nameless books actually take place between books 5 and 6 of Shader (still in first draft), but they don't need you to read Shader first. There are a few references to Shader, but nothing that would ruin the Shader story if you read Nameless first. The Nameless books can actually be read independently of Shader.They are lighter in style - much more old school sword and sorcery, with a dash of irreverent humour.
I've just started work on Nameless 3, btw. There are five planned books for Chronicles of the Nameless Dwarf. After that I'll be bringing out a series of "further adventures", which may well include Shadrak from the Shader books.