Neverwinter Vault have interviewed B G P Hughes on his The Wanderer module. Here's a snip:

2) How does this module compare to the first? What improvements in module design have you learned?
The Wanderer II is somewhat different to the The Wanderer. Firstly part II has moved from the temporary companions of part I to extensive henchmen, with proper interaction and characterisation - they interact with each other, can help the PC and make their own decisions on whether to stay with him/her for example. Secondly in this module the PC no longer is based on Mithri, but is making a journey, so it plays quite differently - different skills, religions and races benefit in Part II. It has different crating systems also. By necessity there is more combat, but I have still ensured there are plenty of alternatives to the sword, and that the module is not linear. I think it also has a different feel to it. I have always been tempted to write a module based on the mines of Moria, but I am too much of a Tolkien purist to mess with his story, so it would be too predictable. Instead I did my own version with The Wanderer II, with my own characters - the aim being a Fellowship of the Ring experience with a proper party feel, without knowing the story in advance. It can play like this even in single player, because I put so much work into the henchmen. I think I've also learnt a bit more about multiplayer along the way also, so that both modules have improved in that department. All my modules are designed to be multiplayer first, but the reality is I get a lot more single player feedback, and this is probably why they make such popular single player modules.

Read the whole thing (http://nwvault.ign.com/index2.shtml) at NWVault.